Hadith 10:1038
Abu Bakr narrated to us, he said: Isa bin Yunus narrated to us, from al-Awza’i, from Yahya bin Abi Kathir, that ‘Amr ibn al-‘As ordered an *umm walad* (a slave woman who has borne a child to her master) who had been manumitted to observe an *‘iddah* (waiting period) of three menstrual cycles. He wrote to ‘Umar [about this], and he [‘Umar] wrote back approving of his opinion.
حدثنا أبو بكر قال نا عيسى بن يونس عن الأوزاعي عن يحيى بن أبي كثير أن عمرو بن العاص أمر أم ولد أعتقت أن تعتد ثلاث حيض وكتب إلى عمر فكتب بحسن رأيه