Yahya related to me from Malik that he heard Ibn Shihab say, "The idda of the divorced woman is reckoned by the menstrual cycles even if she is estranged ." (The reason the idda is normally reckoned by the menstrual cycle is to see whether the woman is pregnant or not.)
Muwatta Malik Book 29, Hadith 67
← Previous Hadith Yahya related to me from Malik that he had heard that Said ibn al-Musayyab and Ibn Shihab and Sulayman ibn Yasar all said, "The idda of the woman with a khul divorce is three periods."

Muwatta Malik Book 29, Hadith 66 Next Hadith → Yahya related to me from Malik from Yahya ibn Said from a man of the Ansar that his wife asked him for a divorce, and he said to her, "When you have had your period, then tell me." When she had her period, she told him. He said, "When you are purified then tell me." When she was purified, she told him and he divorced her.

Malik said, "This is the best of what I have heard about it."

Muwatta Malik Book 29, Hadith 68