Answer:
Ruth was offering herself and the pair had sex
According to many liberal scholars, in ancient idiom, "feet" was a euphemism for the male genitalia. They also support the supposition that the pair had sex by pointing out that, the next morning, Ruth left before daylight, and Boaz said, "Let it not be known that a woman came into the floor." According to conservative scholars, however, "uncovering the feet" was an ancient custom that involved a woman only slightly raising a man's robe and then asking him to (as Ruth does here) throw his skirt over her, as a symbol of the fact that he is willing to take her into his protection as a husband and provider. As evidence, they refer to Ezekiel 16:8, where God (who in the Prophets is often portrayed as the husband of Israel) says that he "spread [his] skirt" over Israel and "entered into a covenant with" them. Conservative scholars also argue that the pair would not likely have had sex on the threshing floor, where other men were also sleeping, and that both characters are portrayed as too virtuous for such an action to be congruous with their characters. Indeed, Boaz's response to Ruth's request was, "I will do to thee all that thou requirest: for all the city of my people doth know that thou art a virtuous woman." He then went on to talk about how he was not the nearest kinsman and did not have the first right to redeem her, but how he would gladly "do the part" (i.e. marry her) if her nearest kinsman refused (Ruth 3:3-13).
