(53) بَابُ الْوُضُوءِ مِنَ النَّوْمِ وَمَنْ لَمْ يَرَ مِنَ النَّعْسَةِ وَالنَّعْسَتَيْنِ أَوِ الْخَفْقَةِ وُضُوءًا
Narrated Anas:
The Prophet (ﷺ) said, "If anyone of you feels drowsy while praying, he should sleep till he understands what he is saying (reciting). (AR)
Reference (AR): Sahih al-Bukhari 213 (AR)
In-book reference (AR): Book 4, Hadith 79 (AR)
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 1, Book 4, Hadith 212 (AR)