Hadith 10:717
Abu Bakr narrated to us, he said: Ibn Idris narrated to us, from Mutarrif, from al-Sha'bi, who said: Every khul' (divorce initiated by the wife) for which a ransom (fida') is taken is a divorce, and it is an irrevocable divorce (taliqa ba'ina).
حدثنا أبو بكر قال نا بن إدريس عن مطرف عن الشعبي قال كل خلع أخذ عليه فداء فهو طلاق وهو تطليقة بائنة