משנה על גיטין 8:1

A woman is betrothed by a denar or the value of a denar, according to the opinion of Beth Shammai. But Beth Hillel says: by a perutah or the value of a perutah. And how much is a perutah? One-eighth of an Italian issar. Beth Shammai says: one may dismiss his wife with an old bill of divorcement, But Beth Hillel forbids it. What is an old bill of divorcement? Whenever he was secluded with her after he has written it for her. One who divorces his wife and she [afterwards] spends a night with him at the [same] inn: Beth Shammai says: she does not require a second bill of divorcement from him. But Beth Hillel says: she requires a second bill of divorcement from him. When [does she require a second bill of divorcement]? When she was divorced after marriage. But if she was divorced after betrothal she does not require from him a second bill of divorcement, since he is not [yet] familiar with her.

A woman is betrothed by a denar or the value of a denar, according to the opinion of Beth Shammai. But Beth Hillel says: by a perutah or the value of a perutah. And how much is a perutah? One-eighth of an Italian issar. Beth Shammai says: one may dismiss his wife with an old bill of divorcement, But Beth Hillel forbids it. What is an old bill of divorcement? Whenever he was secluded with her after he has written it for her. One who divorces his wife and she [afterwards] spends a night with him at the [same] inn: Beth Shammai says: she does not require a second bill of divorcement from him. But Beth Hillel says: she requires a second bill of divorcement from him. When [does she require a second bill of divorcement]? When she was divorced after marriage. But if she was divorced after betrothal she does not require from him a second bill of divorcement, since he is not [yet] familiar with her.