What does Ruth 3:4 mean?
Naomi is giving Ruth instructions. She wants her young Moabite daughter-in-law to marry Boaz, a wealthy, well-respected landowner, but they must act delicately. Ruth needs to approach Boaz near other people, for propriety's sake, but away from listening ears, since her proposal is culturally inappropriate. Naomi's solution is that Ruth will find him when he is asleep on the threshing floor, surrounded by other sleeping harvesters. It's interesting that Naomi's plan puts no pressure on Boaz, but Boaz puts the full-court press on Ruth's other potential suitor (Ruth 4:1–9).As with "drinking" in Ruth 3:3, "uncover his feet" has been erroneously interpreted to infer a sexual act. "Uncover" was often used in the context of "uncovering one's nakedness" which meant shameful sex (Leviticus 20:11). The Hebrew for "feet" was associated with a man's private parts. To "cover one's feet" was a euphemism referring to when a man's robes covered his feet as he squatted to go to the bathroom, thereby uncovering his privates. This phrase is the original Hebrew in 1 Samuel 24:3 when King Saul "relieved himself" in the cave where David was hiding.
That is not what Naomi is saying. The "feet" used to refer to sexual organs is the Hebrew regel (Judges 3:24; 1 Samuel 24:3). Naomi uses margelōṯ, which is better defined as "extremities." The only other passage where the word is used is Daniel 10:6 when it describes the arms and legs (margelōṯ) of an angel. Naomi is not telling Ruth to have sex with Boaz; she's telling her to uncover his feet to expose them to the night air so he will gently wake up without being too startled.
Even more problematically, Naomi tells Ruth to "lie down" after she's uncovered Boaz's feet. Despite what some critics say, Naomi was telling Ruth to lie down on the ground and wait for Boaz to wake up. Ruth would look like any other sleeper on the threshing floor, and when Boaz woke up, she wouldn't appear as a threat. Naomi wasn't telling Ruth to lie on top of Boaz. Naomi wants Ruth married first, not impregnated.
Boaz has always been protective of Ruth and recognizes her integrity. Naomi's comment about how Ruth had worked with Boaz's female servants (Ruth 3:2) refers to when Ruth first started working in his fields. He insisted she stay with the women who could protect her from the men (Ruth 2:8–9). When he awakens, Boaz asks who she is and then immediately blesses Ruth, saying, "May you be blessed by the LORD" (Ruth 3:10), precluding her from having any untoward intentions. And Boaz wouldn't have had sex with her and then offer her to the nearer redeemer (Ruth 4:5).
Naomi's plan doesn't proceed exactly as she anticipates. She tells Ruth to do whatever Boaz tells her—and Ruth does, including waiting until morning to leave and taking the grain Boaz gives her (Ruth 3:13–15). But before that, Boaz agrees to do what she wants him to do (Ruth 3:9, 11). What Ruth wants is for Boaz to buy Naomi's field, give her a son in the name of her late husband, and return the land to that son. Boaz agrees readily. Naomi has no idea that Ruth is doing all of this for her.