"The Sunnah divorce is to divorce her when she is pure (not menstruating) without having had intercourse with her."
Sunan an-Nasa'i Book 27, Hadith 7
← Previous Hadith "The Sunnah divorce is a divorce issued when she is pure (not menstruating) without having had intercourse with her. If she menstruates and becomes pure again, give her another divorce, and if she menstruates and becomes pure again, give her another divorce, then after that, she should wait for another menstrual cycle." (One of the narrators) Al-A'mash said: "I asked Ibrahim, and he said something similar."

Sunan an-Nasa'i Book 27, Hadith 6 Next Hadith → "Tell 'Abdullah to take her back, then, when she has performed Ghusl, let him leave her alone, until she menstruates (again). Then, when she performs Ghusl following that second period, he should not touch her until he divorces her. And if he wants to keep her, then let him keep her. That is the time when Allah has stated that women may be divorced."

Sunan an-Nasa'i Book 27, Hadith 8