Commentary for Kiddushin 36:2

R. Eliezer holds that the text as it is written is authoritative. Thus we can read it without the vocalization, as if it says “bevagdo.” This refers to his betrayal of her. R. Eliezer would hold that once the father has sold her, he can never sell her again. R. Akiva says that the way that the text is read is authoritative. It is read as “bevigdo”—which he reads as “his clothing was upon her.” Once she has been married, she cannot be resold.
R. Shimon says both ways of reading the text are authoritative. Thus she cannot be sold neither after she was married once, nor after she was sold once.