Deuteronomy 25:5-10

I venture to think that this precept had in it somewhat more, than merely what is contained in the obvious letter of it. If it be remembered, that the promise of the woman's seed, bruising the serpent's head, had not in those early ages been so clearly and fully revealed, in what stock or tribe the promised seed should spring, this will serve to show, why it was that the whole nation of the Jews were so very anxious to have children. And, therefore, the preserving the name in Israel was principally with this view. But if we turn to the example of Boaz, in the case of Ruth, where this precept was fully carried into effect, and read what the HOLY GHOST hath been pleased to record concerning this thing: and if we do not forget, at the same time, that Boaz after the flesh, was a progenitor of the LORD JESUS CHRIST; the subject will then open to our view in all its glory. See Ruth 3:9, to the end, and Ruth 4:1 throughout. Blessed JESUS! thou art indeed our near kinsman, our GOD-Redeemer! and thou hast not only married our nature, but hast redeemed our mortgaged inheritance, when all other brethren were incompetent to do it.