The following is a post from Glenn Miller that I publish here for the benefit of the readers since it highlights the amazing compassion and love of the true God.
All of the commentaries I have access to note that the legal provisions in Deut 21.10-14 are ‘exceptional’, ‘remarkable’, ‘compassionate’, or even ‘humanistic'(!):
“The law focuses on the rights of the woman by stating that the man who marries a female prisoner of war and subsequently becomes dissatisfied with her, for whatever reasons, is not permitted to reduce her to slavery. Such a woman had legal rights in ancient Israel, and moral obligations ensue from the fact that the man initiated a sexual relationship with her. Perhaps the most significant conclusion to draw from this text is the respect for the personhood of a captured woman. A primary concern in the laws of Deut 21–25 is for protecting the poor and vulnerable in society from exploitation on the part of the powerful.” [Christensen, D. L. (2002). Vol. 6B: Deuteronomy 21:10–34:12. Word Biblical Commentary (475). Dallas: Word, Incorporated.]
“As in its neighbouring countries, in biblical Israel slaves were also obtained as a result of warfare. Foreign women who became captives of war were regarded as slaves. Sometimes, however, their status ameliorated into that of a free wife. Deut 21:10-14 regulates the case of a man who wished to marry a foreign captive woman.” [WS:WUI, 453]
“Throughout the ancient Mediterranean world, captive women of vanquished peoples were assumed to be the due sexual prerogative of the victors. This law exceptionally seeks to provide for the human rights of the woman who falls into this predicament…the verb ‘inah is also sometimes used for rape, and its employment here astringently suggests that the sexual exploitation of a captive woman, even in a legally sanctioned arrangement of concubinage, is equivalent to rape” [The Five Books of Moses: A Translation with Commentary, Robert Alter, Norton:2004, at Deut 21.10,14]
“Female war captives routinely became concubines of their captors. This law regulates that convention and accords such women dignity and protection against enslavement… Manumission to protect female concubines from being sold as slaves is also prescribed at Exod 21.7-8″ [Jewish Study Bible, JPS]
“The instructions given for the treatment of female captives in Deuteronomy 21:10-14 take it for granted that a conquering army have the right to dispose of the conquered population in any way that it wishes. It is hard for those coming from a different cultural context to see this as anything other than appalling, but this approach would have been unquestioned within the ancient Near East, and we have to see these instructions within that setting. What is remarkable is that although the woman may have had no choice in the matter--the soldier who fancied her has every right to make her this wife–nevertheless her identity as a human being is at least to some extent recognized. She is not to be thrown into the new situation but must be allowed time to mourn for her parents and her past life…Within these oppressive situations the laws are geared to provide at least a level of protection for the women involved…Women who were bought as wives or captured in war and take as wives could not be sold as slaves or even neglected (Ex 21.11; Deut 21.14). [The IVP Women’s Bible Commentary, Kroeger/Evans, pp100,102.]
“The position of a female captive of war was remarkable. According to Deuteronomy 20:14, she could be spared and taken as a servant, while Deuteronomy 21:10-14 allowed her captor to take her to wife. While the relationship of the Hebrew bondwoman was described by a peculiar term, the marriage to the captive woman meant that the man ‘would be her husband and she his wife.” No mention was made of any act of manumission; the termination of the marriage was possible only by way of divorce and not by sale.” [OT:HLBT, p127]
“The space given for weeping is not primarily a period of mourning (though it is perhaps to be assumed that the woman’s father has died in the herem; 20:13, 15). Rather, it is given in compassionate consideration of the large adjustment she must make, and the accompanying trauma. It is an acknowledgment, too, that her former life is ended and a new life is to begin (cf. Ps. 45:10). The hints of compassion breaking through the brutality of the age reflect an awareness of divine compassion, however limited by the thought climate of the times.” [Cairns, I. (1992). Word and presence: A commentary on the book of Deuteronomy. International Theological Commentary (189). Grand Rapids, MI; Edinburgh: W.B. Eerdmans; Handsel Press.]
“Israel’s Treatment of Slaves. Israel’s identity as slaves freed to serve God has a direct bearing on their treatment of slaves, both permanent chattel slaves and fellow Hebrews in bondservice. The treatment of chattel slaves indicates that these slaves are considered human beings. Male slaves are to be circumcised so that they, along with the female slaves, may participate in the Passover meals (Gen 17:13; Ex 12:44), and in the other ceremonial expressions of worship (Deut 12:18; 16:10; Lev 22:11). Slaves must be given rest on the sabbath (Ex 20:10; Deut 5:14). In contrast to the laws of other ancient Near Eastern nations, slaves who flee their owners and come to Israel are not to be returned to their masters, nor are they to be oppressed, but they are to be allowed to live wherever they please (Deut 23:15–16). If an Israelite man desires to take a non-Israelite captive woman as his wife, he has to allow her a month of preparation and mourning for her parents before he marries her. Subsequently, if he becomes dissatisfied with her, he may not sell her as a slave but must allow her to go free (Deut 21:10–14).” [Alexander, T. D., & Baker, D. W. (2003). Dictionary of the Old Testament: Pentateuch (781). Downers Grove, IL: InterVarsity Press.]
“Marriages were normally arranged between families, outside the prohibited degrees of kinship in the bêt-ʾāb (Leviticus 18 and 20), but usually within the kinship of the mišpāḥâ. The latter was obligatory in the case of marrying daughters who, in the absence of sibling brothers, had inherited the land of their father (Numbers 36). Exceptions would have been marriage as the result of prior rape (Exod 22:16f., amended in Deut 22:28f.), and the taking of a wife from captives of war (which was hedged with humanitarian restrictions on mere rapacity, Deut 21:10–14). ” [Wright, C. J. H. (1992). Family. In D. N. Freedman (Ed.), . Vol. 2: The Anchor Yale Bible Dictionary (D. N. Freedman, Ed.) (766). New York: Doubleday. ]
One writer (non-conservative) called it ‘an instruction in humanism’, as noted by someone interacting with that view:
“It has long been argued that the book of Deuteronomy presents a “humanitarian vision” for community life in Israel. Indeed, Moshe Weinfeld argues that “the primary aim of the Deuteronomic author is the instruction of the people in humanism, and in furtherance of this goal he adapts the various literary traditions which were at his disposal.” Weinfeld divides the humanist laws of Deuteronomy into three major categories. They are:
(1) Laws emphasizing the value of human life and human dignity. Examples of these laws include the treatment of runaway slaves (Deut 23:16) and women war captives (Deut 21:10–14); restrictions on excessive corporal punishment, lest the victim be “degraded” (Deut 25:1–3); proper disposition of a corpse after an execution (Deut 21:22–23); and the regulation of the construction of roof parapets in order to minimize danger to human life (Deut 22:8).
(2) Laws dealing with interpersonal social relations. These include calls for assisting aliens, orphans, widows, and the poor, as well as enjoining a positive attitude toward these marginal groups (Deuteronomy 15; etc.), regulation of property rights (Deut 23:25), and warnings regarding the treatment of a hated wife and her son (Deut 21:15–16).
(3) Laws dealing with the humane treatment of animals. Examples include prohibition of taking both mother and her young from the nest (Deut 22:6–7), and the requirement to refrain from muzzling an ox while it is treading out grain.
“Each category of laws may be seen as having a practical, human-centered basis rather than explicitly religious or theological ones, in Weinfeld’s view.”
[“Social Justice And The Vision Of Deuteronomy”, Peter T. Vogt; Journal of the Evangelical Theological Society Volume 51. 2008 (1) (33). Lynchburg, VA: Evangelical Theological Society.
The only resource I have which seems to indicate some continuity with ANE practice says this about the passage:
“Rights of Captive Women. 21:10–14. treatment of captive women. Part of warfare is the disposition of prisoners. Some female captives could expect to serve as slaves (2 Kings 5:2–3), but many would also be taken as wives by the soldiers. The Deuteronomic law deals with the transformation process as these women were adopted into Israelite society. This included the shaving of the head, a change of clothing and a period of mourning marking the death of the woman’s old life and the beginning of a new one (compare Joseph’s transformation in Gen 41:41–45). The Mari texts also provide clothing and a job to captive women. The rights extended to the former captive after she has married are similar to those of Israelite women and are designed to demonstrate that there is no reduction of her status if a divorce occurs. Similar concerns are reflected in the Middle Assyrian laws, which require former captives who are now married to dress like all Assyrian women of that class.” [Matthews, V. H., Chavalas, M. W., & Walton, J. H. (2000). The IVP Bible background commentary: Old Testament (electronic ed.) (Dt 21:9–14). Downers Grove, IL: InterVarsity Press.]
I have searched everywhere I can find, but I cannot find any reference to close parallel materials in the Mari materials (so far), nor in the MAL–so I cannot see how close these are. They are not mentioned in any of the commentaries I can find (so far), other than noted below on the purification process.
The Mari texts describe a similar purification rite (but without any indication of mourning):
“Rachel’s theft of her father’s household gods may have something to do with the law’s demands that the woman sever contact with her past—shave her head, pare her nails, put off her captive’s garb, and bewail her parents for a month. For a parallel in the Mari texts, in which hair and clothing were removed during a rite symbolizing severance from homeland, see du Buit, RB 66 (1959) 576–77 (cited by Carmichael, LNB, 141 n. 5).”, [WBC, in loc]]
“The acts of “shaving her head, paring her nails, and putting off her captive’s garb” are usually interpreted as part of the woman’s mourning process. “The shaving of the head and putting off of the clothes is referred to in the Mari texts where it has the purpose of getting rid of everything that would remind the captive of home” (Mayes  303; cf. du Buit, RB 66  576–77). Rabbi Akiba thought they were intended to make the woman less attractive to her captor (Sifre 212; see Tigay  194, 381 n. 29). The “captive’s garb” (שׂמלת שׁביה) is simply the clothes the woman was wearing when taken captive.” [WBC, in loc]
The captives of Mari (some) were given a ‘job’ in the slave textile mills:
“Of somewhat earlier date is the Mari material (18th cent BCE) which informs us on the harem of Zimri-Lim…Zimri-Lim’s harem was occupied not only by his wives, but also by women of lower status. Some of these women were of local origin, but others were foreigners, usually prisoners of war. These female captives, who generally were of exceptional beauty, escaped the fate of being put to work in the royal textile factories and became a royal concubine.” [WS:WUI, 375]
The Middle Assyrian Laws do have regulations on veiling of the different classes of women (e.g MAL A 40), but I cannot find anything related to mourning periods, complete freedom upon divorce, purification rituals, etc.
The most authoritative work on ANE law at this point is the 2-volume work edited by Raymond Westbrook, which discusses the law codes and cases under a common outline (e.g. Citizenship is under bullet 4.1, Inheritance is under 6.2). [HI:HANEL]
Here is the bullet which treats our passage in Israel:
“188.8.131.52. Two laws discuss the treatment of unfree women acquired as wives in divergent ways… Exod 21:7-10…Deuteronomy provides for capturing a wife in warfare (Deut. 21:10-14). Brought home, she was to perform transition rituals–shaving her head, cutting her fingernails…As with the ‘amah of Exodus, the captive bride could not be treated as an ordinary slave and sold. Changing his mind was considered abuse, and if he did not want her, she would be free.” [HI:HANEL,pp1008,1009]
When we try to find the item 184.108.40.206 in the other chapters about other nations/empires, we come up empty handed–there are no such sections there.
When we look at the index entry for this section (“Prisoners of War, as captive brides”) only Israel is mentioned–there is nothing about Mari or Middle Assyrian Law.
When we broaden the search within the work, we can perhaps understand this ‘exceptional’ character of the law a bit better (at least for Mesopotamia, the relevant area):
“War is only mentioned as a source of slavery for public institutions” (p199; Note that this would mean that captive women were given a ‘job’ in government/temple-funded operations and ‘clothed’ with official garb/uniforms–as opposed to the clothing of a foreign culture. This is attested widely in the non-legal royal literature, with the Mari palace having over 400 such ‘domestics’. )
“Since a female slave was property, her owner could exploit her sexuality and her fertility like any other beneficial aspect of property. She could thus be made her owner’s concubine. Where concubinage resulted in motherhood, the slave might be accorded some qualified protection from the consequences of her status as property. She and her offspring might even gain their freedom on the death of the master/father [LH 171]. The intention appears to have been to accord the slave concubine some of the rights of a married woman, not including, the sources emphasize, the right of inheritance for her children.” (p44, in the chapter “The Character of Ancient Near Eastern Law”; note that this is merely SOME rights, whereas the Hebrew passage is FULL rights.]
But the most telling/helpful passage is the one (in the same chapter on the ‘overall character’ of ANE law):
“9.3.4. Nothing certain can be said about the rules of war. A declaration of war sometimes preceded hostilities, but there appears to have been no general observation. Prisoners of war were at the mercy of their captors, to treat at their discretion. They were either killed, enslaved (often being blinded), or ransomed. Civilians were regarded as legitimate booty. Humane treatment seems to have depended on political expediency and internal inhibitions rather than on recognized legal rules.” (p86).
This makes it clear that the very fact of a regulation for humane treatment in Deut was ‘exceptional’, since such legal structures do not even appear in other cultures (ie, ‘humane’ treatment was not a legal requirement, but rather a matter of ‘individual choice’…).
So, the text still stands far above the other cultures of the day, and reveals that God set boundaries for His people’s conduct.