Who art thou, my daughter? either, first, She did not distinctly know who she was, because it was dark, and so calls her daughter only in general, as elder women call the younger. But she could as easily have discerned who she was, as what her age was. Or, secondly, This is not a question of doubting, but of wonder, as if she had said, Art thou in very deed my daughter? I can hardly believe it. How comest thou hither in this manner, and thus early?
Related Commentaries of Ruth 3:16
Ruth 3:16
16 And when she came to her mother in law, she said, Who art thou, my daughter? And she told her all that the man had done to her.