Musannaf Ibn Abi Shaybah 8021 — How many rakahs of Duha are prayed

Ibn Abi Layla said: No one told us about the Duha prayer of the Prophet (peace and blessings be upon him) except Sayyidah Umm Hani (may Allah be pleased with her). She said: The Prophet (peace and blessings be upon him) came to my house on the day of the Conquest of Makkah. He took a ritual bath (ghusl), then prayed eight rak'ahs of the Duha prayer, keeping the bowing and prostration short in them. I never saw him pray that prayer before or after that day.