Anas bin Malik reported,

The Prophet ﷺ fell from a horse onto his right side. People came to visit him while he was recovering, and when the time for prayer arrived, he led them in prayer while seated. After completing the prayer, he said, "The imam is appointed only to be followed. When he bows, bow. When he rises, rise. And when he says, 'Allah hears whoever praises Him,' say, 'Our Lord, to You belongs all praise.'"

Nasai 1062

Sahih

أخبرنا هناد بن السري عن ابن عيينة عن الزهري

عن أنس

أن النبي ﷺ سقط من فرس على شقه الأيمن فدخلوا عليه يعودونه فحضرت الصلاة فلما قضى الصلاة قال إنما جعل الإمام ليؤتم به فإذا ركع فاركعوا وإذا رفع فارفعوا وإذا قال سمع الله لمن حمده فقولوا ربنا ولك الحمد

النسائي 1062صحيح
Contents
Reference
Commentary
Ayat
Collection
Sunan Nasai Sughra
Book
Placing the hands between the knees in bowing
Chapter
What the follower says
Numbering
Darussalam 1062
Nasai 1062