Deuteronomy 25:5-10 -

Levirate marriages . If a man who was married died without issue, his surviving brother was required to marry the widow, so as to raise up a successor to the deceased, who should be his heir. The brother who refused this duty must be publicly disgraced. The design of this institution—which was not originated by Moses, but came down from early times ( Genesis 38:8 ), and is to be found amongst ether nations than the Jews, and that even in the present day—was to preserve a family from becoming extinct and to secure the property of a family from passing into the hands of a stranger. The notion that the usage "had its natural roots in the desire inherent in man who is born for immortality, and connected with the hitherto undeveloped belief in an eternal life, to secure a continued personal existence for himself and immortality for his name through the perpetuation of his family, and in the life of the son who took his place" (Keil), seems wholly fanciful.