Deuteronomy 21:12

Then thou shalt bring her home to thine house; and she shall shave her head, and pare her nails;

The verse belongs to Moses' rehearsal of the wonderful things God had done for His people and the chief laws connected with Israel, spoken before Israel crossed the Jordan into the promised land to remind them of the lessons of forty years in the wilderness and to impress upon them the sacred import of God's holy law and the necessity of keeping it. It belongs to the special instruction in Deuteronomy 18-26, made up of various directions given by Moses, great principles by which questions are to be decided, and various laws repeated for the government of Israel and the regulation of their worship. It gives the rule for treating a captive woman brought into an Israelite home, that she shall shave her head and pare her nails, as part of the instructions on how Israelites should deal with female captives, some of whom might become wives.

The shaving of the head and paring of the nails were ceremonies signifying that she had become a proselyte to the Jewish religion and was separated from her idolatrous kin, after which she could be taken into an Israelite family and treated as one of the nation. Such captives were not for immoral use, for the law forbids using a captive woman as an object of lust and requires bringing her into the home and taking her as a wife. Brought into Israelite homes, such captives would be kept as servants, reared in virtue, and lead a life many times better than in their own nation.

If the marriage does not work and the husband later rejects her, he may not enslave her, sell her as a slave, or make merchandise of her because he has humbled her, but must let her go free, even as an Israelite woman, where she wishes. The law is in harmony with justice and is far better than slavery, showing a regard for women and a mercy far above that of all foreign and heathen nations around Israel and their practices. It was the best God could do with Israel at that time without destroying free will, as He always does with every nation, for after their long sojourn in Egypt Israel were but little removed from the heathen themselves, and God suffered many such things because the people could not be brought to see higher right, since He will not force men to be machines. The merciful character of such laws proves their divine origin, and as light and salvation to those in darkness they led on to still greater light.