ייִדישער מחשבֿה אויף רות 1:14

She left from the place that was there, and there were two daughters-in-law with her, and they went on their way to return to the land of Yehudah (Ruth 1:7). They lifted up their voices, and they cried, and Orpah kissed her mother-in-law, and Ruth clung to her (Ruth 1:14).

Orpah kissed her mother-in-law (Ruth 1:14). She said, "It is the law, and I accept it." She returned to her mother's house.

Ruth interpreted these things: "Ish" (the word for "man") includes "ishah" (the word for "woman"). Just as a man leaves his family and clings to his woman, so too does a woman leave her family and cling to her man. When "b'ishto" (to his woman) is said — it includes his father-in-law and his mother-in-law and the descendants of his family. Immediately (i.e. as soon as Ruth made this point, the narrator said) — "davkah bah" (she clung to her).