Adam Clarke on Ruth 2:10

Then she fell on her face - Prostrated herself, as was the custom in the East when inferiors approached those of superior rank. The Targum adds to the conversation between Ruth and Boaz: "How, says she, have I obtained grace in thy sight, that thou shouldest acknowledge me who am a stranger and one of the daughters of Moab, of whom it is said, The unclean shall not enter into the congregation of the Lord? And Boaz, answered, It has been certainly told me by the word of the wise, that what the Lord hath decreed, he hath not decreed concerning the women but the men. And it hath been surely said to me by prophecy, that kings and prophets shall proceed from thee because of the good which thou hast done," etc.