Hadith 10:1196
Abu Bakr narrated to us, he said: Mu'tamir ibn Sulayman narrated to us, from Bard, from Makhul and al-Zuhri: They both said: The woman begins her waiting period ('iddah) from the day he died or divorced.
حدثنا أبو بكر قال نا معتمر بن سليمان عن برد عن مكحول والزهري قالا تعتد المراة من يوم مات أو طلق