Rif Gittin 8a {17b}

8a

{Gittin 17b}

אבל משום פירות לא קסבר יש לבעל פירות עד שעת נתינה
ור' שמעון בן לקיש אמר משום פירות קסבר אין לבעל פירות משעת כתיבה
אבל משום בת אחותו לא קסבר זנות לא שכיחא

but he {Rabbi Yochanan} is not concerned about increase. For he holds that the husband has the increase until the time of the giving {over of the get, not only until the time of the writing of the get}.
And Rabbi Shimon ben Lakish said because of the increase. For he holds that the husband does not get the increase from the time of the writing and on. But he is not concerned with the reason of {the man having married} his sister's daughter, for infidelity is not common.