Chapter 27: The Book of Divorce
It was narrated from 'Aishah that a man divorced his wife three times and she married another husband who divorced her, before having intercourse with her. The Messenger of Allah was asked: "Is she permissible for the first (husband to remarry her)?" He said: "No, not until he tastes her sweetness as the first tasted her sweetness."
Sunan an-Nasa'i 3412