From Sahih Bukhari (Hadith 4292):
Narrated Ibn Abi Laila:None informed us that he saw the Prophet (ﷺ) offering the Duha (i.e. forenoon) prayer, except Um Hani who mentioned that the Prophet (ﷺ) took a bath in her house on the day of the Conquest (of Mecca) and then offered an eight rak`at prayer. She added, "I never saw the Prophet (ﷺ) offering a lighter prayer than that prayer, but he was performing perfect bowing and prostrations
Reference: Bukhari 4292