Related for Kiddushin 9:20

And whence is it derived that she is also acquired by a writ (shtar)? It follows, viz.: If money, which does not release (a woman from marriage), acquires, then shtar (a writ [of divorce]), which does release a woman, how much more so should it acquire! (No,) this may be true of money, which acquires hekdesh (consecrated property) and second tithe, but not with shtar, which does not acquire hekdesh and second tithe. It must, therefore, be written (Ibid.) "then he shall write for her a scroll of divorce, and he shall place it into her hand, and he shall send her from his house. This one's coming in (to marriage) is compared to her going out (viz. Ibid. 2). Just as her going out is with a shtar (i.e., a get), so, her coming in.