Megillat Rut Chapter 3

(1) Naomi, her mother-in-law, said to her, “Daughter, I must seek a home for you, where you may be happy. (2) Now there is our kinsman Boaz, whose girls you were close to. He will be winnowing barley on the threshing floor tonight. (3) So bathe, anoint yourself, dress up, and go down to the threshing floor. But do not disclose yourself to the man until he has finished eating and drinking. (4) When he lies down, note the place where he lies down, and go over and uncover his feet and lie down. He will tell you what you are to do.” (5) Try translating! (6) Try translating! (7) Boaz ate and drank, and in a cheerful mood went to lie down beside the grainpile. Then she went over stealthily and uncovered his feet and lay down. (8) In the middle of the night, the man gave a start and pulled back—there was a woman lying at his feet! (9) “Who are you?” he asked. And she replied, “I am your handmaid Ruth. Spread your robe over your handmaid,^-a for you are a redeeming kinsman.” (10) He exclaimed, “Be blessed of the LORD, daughter! Your latest deed of loyalty is greater than the first, in that you have not turned to younger men, whether poor or rich. (11) And now, daughter, have no fear. I will do in your behalf whatever you ask, for all the elders of my town^-c know what a fine woman you are. (12) But while it is true I am a redeeming kinsman, there is another redeemer closer than I. (13) Stay for the night. Then in the morning, if he will act as a redeemer, good! let him redeem. But if he does not want to act as redeemer for you, I will do so myself, as the LORD lives! Lie down until morning.” (14) So she lay at his feet until dawn. She rose before one person could distinguish another, for he thought, “Let it not be known that the woman came to the threshing floor.” (15) And he said, “Hold out the shawl you are wearing.” She held it while he measured out six measures of barley, and he put it on her back.
When she got back to the town, (16) she came to her mother-in-law, who asked, “How is it with you (lit. "who are you"), daughter?” She told her all that the man had done for her; (17) and she added, “He gave me these six measures of barley, saying to me, ‘Do not go back to your mother-in-law empty-handed.’” (18) And Naomi said, “Stay here, daughter, till you learn how the matter turns out. For the man will not rest, but will settle the matter today.”

The nice ones that you haven't harvested in.

Then she uncovered his feet and lied down etc., and at the middle of the night he gave a start!

For he got up to study Torah.

....

But what is the meaning of And he gave a start? He thought, Perhaps she is a demon! He then placed his hand on her head and realized - It's a woman! For demons don't have any hair.

As God lives: She said to him, “You are dismissing me with words.” He jumped up and swore to her that he would not dismiss her with words.

Then he said, Give over your shawl.

The masculine form is written (hav), but we read it in the femenine form (havi). In truth, he was speaking in the masuline, so that no one would recognize what was going on.

Then she came to her mother-in-law, and she said, Who are you? (3:15)

Did she not recognize her?

One could answer that the day was still not light enough, and Naomi was still sleeping.

Or one could say that she said to her, Who are you? Which meant, Are you available? Or are you now married? To which she responded everything that the man did for her.