Yosef Karo, Shulchan Aruch — Even HaEzer27
“ I am betrothed to you Then nothing has happened even if he was originally speaking with her about marriage-related matters because it is written “when a man take,” not “when he takes himself.”Seif 7: If she gives him money and she says I am betrothed to you, she is not betrothed. Seif 8: If he gave her [money] and she speaks [i.e. the engagement formula] , if he was speaking with her about matters of betrothal, it is definitely betrothal, and if not, it is a case of doubtful betrothal. ”
