The Messenger of Allah ﷺ was on the pulpit when he recited Surah Sad. When he reached the verse of prostration, he descended and prostrated, and the people prostrated along with him.On another day, he recited it again, and when he reached the verse of prostration, the people prepared themselves to prostrate. The Prophet ﷺ said, "This is only the repentance of a prophet, but I saw you preparing yourselves to prostrate." So he descended and prostrated, and they prostrated with him.
قرأ رسول الله ﷺ وهو على المنبر {ص} فلما بلغ السجدة نزل فسجد، وسجد الناس معه، فلما كان يوم آخر قرأها فلما بلغ السجدة تشزن الناس للسجود، فقال النبي ﷺ: إنما هي توبة نبي، ولكني رأيتكم تشزنتم للسجود فنزل فسجد، وسجدوا.
Abu Dawud (1410) narrated it from Ahmad bin Salih, who said, Ibn Wahb narrated to us, who said, Amr, meaning Ibn Harith, informed me, from Saeed bin Abu Hilal, from Iyad bin Abdullah bin Saad bin Abu Sarh, from Abu Saeed, and he related it.Its isnad is hasan because of Saeed bin Abu Hilal, for his hadith is hasan. Ibn Khuzayma (1455), Ibn Hibban (2765), and Hakim (2/431-433) all graded it sahih, all of them through the route of Saeed bin Abu Hilal. Hakim said, "Sahih according to the criteria of the two Shaykhs." Nawawi said in Khulasa (2140), "Its isnad is sahih according to the criteria of Bukhari."His saying "tashazzan" is written with a ta marked with two dots above, a dotted shin, and a doubled zay, and it means "he prepared himself."