Muwatta Imam Malik Book of Divorce, Hadith 60

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."

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، وَابْنِ، شِهَابٍ وَسُلَيْمَانَ بْنِ يَسَارٍ أَنَّهُمْ كَانُوا يَقُولُونَ عِدَّةُ الْمُخْتَلِعَةِ ثَلاَثَةُ قُرُوءٍ .