"The Messenger of Allah (ﷺ) used to pray when I was lying in front of him as the bier is placed (in front of the Imam), and when he wanted to pray Witr he would nudge me with his foot."
Sunan an-Nasa'i Book 1, Hadith 167
← Previous Hadith "We went out as a delegation and when we arrived with the Messenger of Allah (ﷺ) he accepted our oath of allegiance and we prayed with him. When he had finished the prayer, a man who looked like a Bedouin came to him and said: 'O Messenger of Allah, what do you think about a man who touched his penis during the Salah?' He said: 'It is just a part of you,' or 'a piece of you.'"

Sunan an-Nasa'i Book 1, Hadith 166 Next Hadith → "I remember lying in front of the Messenger of Allah (ﷺ), and the Messenger of Allah (ﷺ) was praying. When he wanted to prostrate he would nudge my foot and I would draw it up (out of the way) until he had finished prostrating."

Sunan an-Nasa'i Book 1, Hadith 168