4 And it shall be, when he lieth down, that thou shalt mark the place where he shall lie, and thou shalt go in, and uncover his feet, and lay thee down; and he will tell thee what thou shalt do.
What does Naomi suggest to her daughter-in-law? When Ruth heard her mother-in-law saying, “Our neighbor is a true man,” she was reminded of his great kindness and thought to want him [to be] married to her in law, so that she might keep up the memory of the dead. Therefore, she [Naomi] suggests to her that she sleep at Boaz’s feet, not that she might sell her body (for the words of the narrative signify the opposite); rather, she trusts the man’s temperance and judgment. Moreover, the actions corroborate the words.
[AD 458] Theodoret of Cyrus on Ruth 3:1-4