On the day of the Conquest the Messenger of Allah ﷺ prayed the voluntary Duha prayer, eight rakahs, giving the salam after every two rakahs.Ahmad bin Salih's wording was, "On the day of the Conquest the Messenger of Allah ﷺ prayed the voluntary Duha prayer."Naeem bin Hammar reported, "I heard the Messenger of Allah ﷺ say, 'Allah says, "Son of Adam, do not fall short of four rakahs at the start of your day, and I will take care of you to its end."'"Ibn Sarh's wording was, "Umm Hani said, 'The Messenger of Allah ﷺ came in to me,'" and he did not mention the voluntary Duha prayer, but the meaning was the same.
حدثنا أحمد بن صالح وأحمد بن عمرو بن السرح قالا حدثنا ابن وهب حدثني عياض بن عبد الله عن مخرمة بن سليمان عن كريب مولى ابن عباس عن أم هانئ بنت أبي طالب أن رسول الله ﷺ يوم الفتح صلى سبحة الضحى ثماني ركعات يسلم من كل ركعتين قال أحمد بن صالح إن رسول الله ﷺ صلى يوم الفتح سبحة الضحى فذكر مثله قال ابن السرح إن أم هانئ قالت دخل علي رسول الله ﷺ ولم يذكر سبحة الضحى بمعناه
Chain evaluation, hasan. Ibn Majah reported it in the Book of Establishing the Prayers, chapter on what has been said about the night and day prayers being performed two by two, hadith 1323, from the hadith of Ibn Wahb, with this same chain. Ibn Khuzayma graded it sahih, hadith 1234, and the hadith has corroborating reports in Bukhari, hadith 280, and elsewhere.