People had disputed about the minbar and what kind of wood it was made from, so they asked Sahl about it.He said, "By Allah, I know exactly what it is made of. I saw it on the very first day it was placed, and the first day the Messenger of Allah ﷺ sat upon it.The Messenger of Allah ﷺ sent word to a certain woman," whom Sahl named, saying, "Instruct your carpenter slave to make me some wooden steps that I may sit upon when I address the people."So she ordered him, and he made it from the tamarisk wood of the forest, then brought it to her. She then sent it to the Prophet ﷺ, who ordered it to be placed here.I saw the Messenger of Allah ﷺ pray upon it. He pronounced the takbir while standing on it, then bowed while still upon it, then stepped backwards down and prostrated at the base of the minbar, then returned to it. When he finished, he turned to the people and said, "People, I have only done this so that you may follow me and learn my prayer."
حدثنا قتيبة بن سعيد حدثنا يعقوب بن عبد الرحمن بن محمد بن عبد الله بن عبد القاري القرشي حدثني أبو حازم بن دينار أن رجالا أتوا
وقد امتروا في المنبر مم عوده فسألوه عن ذلك فقال والله إني لأعرف مما هو ولقد رأيته أول يوم وضع وأول يوم جلس عليه رسول الله ﷺ أرسل رسول الله ﷺ إلى فلانة امرأة قد سماها سهل أن مري غلامك النجار أن يعمل لي أعوادا أجلس عليهن إذا كلمت الناس فأمرته فعملها من طرفاء الغابة ثم جاء بها فأرسلته إلى النبي ﷺ فأمر بها فوضعت هاهنا فرأيت رسول الله ﷺ صلى عليها وكبر عليها ثم ركع وهو عليها ثم نزل القهقرى فسجد في أصل المنبر ثم عاد فلما فرغ أقبل على الناس فقال أيها الناس إنما صنعت هذا لتأتموا بي ولتعلموا صلاتي
Bukhari transmitted it in the Book of Jumuah, Chapter on the sermon from the pulpit, hadith 917, and Muslim in the Book of Mosques, Chapter on the permissibility of taking one or two steps during the prayer... etc, hadith 544, both of them from Qutayba bin Saeed with this chain.