Busra bint Safwan bin Nawfal · The Book of Ghusl and Tayammum

"I prayed with the Prophet (ﷺ) one night, and I stood on his left, but he made me stand on his right, and he prayed. Then he reclined on his side and took a nap, then the Mu'adhdhin came to him and he prayed, and did not perform Wudu'."

"If anyone of you feels drowsy during his Salah, let him go and take a nap."

"If any one of you touches his private part with his hand, let him perform Wudu'."