The Prophet ﷺ said, "We have entered the morning upon the natural way of Islam, upon the word of pure devotion, upon the religion of our Prophet Muhammad ﷺ, and upon the creed of our father Ibrahim, who was upright, a Muslim, and was not among the polytheists."
قال حدثنا محمد بن جعفر حدثنا شعبة عن سلمة بن كهيل عن ذر
عن النبي ﷺ أنه قال أصبحنا على فطرة الإسلام وعلى كلمة الإخلاص وعلى دين نبينا محمد ﷺ وعلى ملة أبينا إبراهيم حنيفا مسلما وما كان من المشركين
Its isnad is sahih. It is found in Nasai in Sunan al-Kubra 6/4, no. 9830, in the chapter on the deeds of the day and night, in Darimi 2/378, no. 2688, and in Ibn Abu Shayba 9/177, no. 2091, in the chapter on manners. Haythami said, 10/116, "The narrators of Ahmad and Tabarani are the narrators of sahih."