Ruth 4:5
Then said Boaz, What day thou buyest the field of the hand of Naomi, thou must buy it also of Ruth the Moabitess, the wife of the dead, to raise up the name of the dead upon his inheritance.
Then said Boaz,.... In order to try the kinsman, whether he would abide by his resolution, he acquaints him with what he had as yet concealed:
What day thou buyest the field of Naomi, thou must buy it also of Ruth the Moabitess, the wife of the dead; the wife of Mahlon, who was dead, the eldest son of Naomi, and so his widow, Ruth the Moabitess, had the reversion of the estate; wherefore the purchase must be made of her as well as of Naomi, and the purchase could not be made of her without marrying her; which, though no law obliged to, yet it seems to be a condition of the purchase annexed to it by Naomi, that she would sell it to no man, unless he would consent to marry Ruth, for whose settlement she had a great concern, having been very dutiful and affectionate to her; which is clearly intimated in the next clause:
to raise up the name of the dead upon his inheritance; and so Naomi had another end to answer thereby, not only to provide a good husband for her daughter-in-law, but to perpetuate the name of her son, agreeably to the design of the law in Deuteronomy 25:5.