The Messenger of Allah ﷺ performed the prayer on the day of the Conquest, and he placed his sandals on his left side.
أخبرنا عبيد الله بن سعيد وشعيب بن يوسف عن يحيى عن ابن جريج قال أخبرني محمد بن عباد عن عبد الله بن سفيان
أن رسول الله ﷺ صلى يوم الفتح فوضع نعليه عن يساره
Its isnad is sahih. Abu Dawud narrated it in the Book of Prayer, Chapter on Praying in Sandals, no. 648, and Ibn Majah in the Book on Establishing the Prayers, Chapter on What Has Been Said About Where the Sandals Are Placed... etc, no. 1431, from the hadith of Yahya bin Saeed Qattan with this same wording. It is also found in Kubra, no. 852, and Ibn Khuzayma graded it sahih, no. 1014, 1015, as did Ibn Hibban (Ihsan), no. 2186.