Thurs Sotah 31

If a little birdie tells us he needs to divorce her but she receives her Kesuvah. R' Yehoshua says only if the yentas talk about her.

Rashi learns this refers to finding out she secluded. Although if the birdie (a slave) says they secluded you can bring her to drink the Mai Marim, we refer to where he doesn't want to. That's why he's still needs to give the kesuvah, since she had a way to show her innocence and he ruined it.

Tosfos asks: however, in R' Yehoshua's case, we say that it's too strong of evidence and she doesn't drink. So divorce is an order. Why does he needs to pay a Kesuvah? We must say that the Yenatas were not telling us that she secluded, but rather they just remark on her general Pritzos.

Tosfos argues with Rashi: that even the Tana Kama we can say the little birdie didn't say she secluded herself, but rather in her general Pritzos. Although it doesn't make her technically Assur, but after Kinoi combined with waht the birdie said, she's highly suspicious, so the right thing is to divorce her. Since it doesn't technically Assur her, she gets her Kesuvah.