(Exodus 21:7) "And if a man sells his daughter as a maid-servant" — He sells her once as a maid-servant, and not twice. R. Yossi Haglili says: We find, then, that he (a father) can betroth her betrothal after betrothal (i.e., if she were divorced after the first betrothal, he may betroth her to another), and betrothal after (having sold her as a) maid-servant, but not maid-servant after maid-servant, and, it goes without saying, not maid-servant after betrothal.