Albert Barnes' Notes on the Whole Bible - Deuteronomy 25:5-10
The law of levirate marriage. The law on this subject is not unique to the Jews, but is found (see Genesis 38:8) in all essential respects the same among various Oriental nations, ancient and modern. The rules in these verses, like those upon divorce, do but incorporate existing immemorial usages, and introduce various wise and politic limitations and mitigations of them. The root of the obligation here imposed upon the brother of the deceased husband lies in the primitive idea of childlessness... read more
The Pulpit Commentary - Deuteronomy 25:7-10
If the man refused to marry the widow of his deceased brother, he was free to do so; but the woman had her redress. She was to bring the matter before the eiders of the town, sitting as magistrates at the gate, and they were to summon the man and speak to him, and if he persisted in his refusal, the woman was to take his shoe from off his foot, and spit before his face, and say, So shall it be done unto that man that will not build up his brother's house. The taking off of the shoe of the... read more