(29) باب الأَمْرِ بِالْوُضُوءِ مِنَ النَّوْمِ
It was narrated from Anas that the Messenger of Allah (ﷺ) said:
"If anyone of you feels drowsy during his Salah, let him go and take a nap."
Reference: Sunan an-Nasa'i 443
In-book reference: Book 4, Hadith 49
English translation: Vol. 1, Book 4, Hadith 444