Deuteronomy 25:7
And if the man like not to take his brother’s wife, then let his brother’s wife go up to the gate unto the elders, and say, My husband’s brother refuseth to raise up unto his brother a name in Israel, he will not perform the duty of my husband’s brother.
Deuteronomy stands as the fifth and last book of the Pentateuch, containing the second of three addresses given by Moses just before his death, with chapters 5 to 26 reviewing the law for the new generation, from which repetition the book takes its name meaning second law or duplicate of the law. Within that review, the verse belongs among the repeated laws of chapters 23-25 dealing with duties between man and man and between man and God. The levirate marriage requirement it states did not originate with Moses but was already recognized in patriarchal times.
The duty is that when a man dies without an heir, having no children, his brother should marry the childless widow to raise up seed, a name, and an heir in Israel for the dead brother. The firstborn of that union is counted as the deceased man's son and heir, so that the homestead and inheritance in the land of Canaan is retained in the family instead of passing into other hands. This preserves the deceased man's name and inheritance and provides the Israelite background for the right and duty of a near kinsman, a Go'el, to redeem the inheritance and raise up the dead man's name upon it. Perpetuating the dead kinsman's family and inheritance by taking the childless widow was his chief obligation, for keeping every family alive in Israel was of supreme importance.
If the man likes not to take his brother's wife, the widow may go up to the gate, the town gate, to the elders and declare that her husband's brother refuses to raise up a name in Israel and will not perform the duty of a husband's brother. The refusing kinsman is then brought before the elders at the gate, where he receives the legal tokens of contempt due to the man that will not build up his brother's house. He is publicly insulted, exposed to public contempt, and his name becomes a reproach.
Refusal was driven by cost to the kinsman himself, because the first son born of such a marriage is counted as the deceased man's son and inherits his land while only later sons belong to the kinsman himself. If only one son is born the kinsman is therefore reckoned childless without an heir to preserve his own name and family. Refusing this duty brings not only human contempt but the displeasure of the Lord, as seen in the death inflicted for the same refusal in the case of Onan. Under this law Tamar's resort to strategy to secure the rights of which Judah had fraudulently deprived her was less reprehensible than under other circumstances, and sons born of such a union are reckoned legitimate, with one of them in the ancestry of Christ.
The verse belongs to the Mosaic law behind the Sadducees' question about marriage in the resurrection, concerning the duty of a brother to marry his deceased brother's childless wife and preserve his brother's name. They presented the case of seven brethren who each in turn married the same wife and died without issue and asked whose wife she shall be in the resurrection. Jesus answered that objection that it errs from not knowing the Scriptures nor the power of God, and that the dead are raised up by the power of God. For those accounted worthy to obtain that world and the resurrection from the dead this arrangement will be unnecessary, because they cannot die anymore and there is no danger of the inheritance passing out of the family. Each will build and inhabit and plant and eat in the restored new earth and keep his own portion forever.