The Prophet (ﷺ) said, "If anyone of you feels drowsy while praying, he should sleep till he understands what he is saying (reciting).
Sahih al-Bukhari Book 4, Hadith 79
← Previous Hadith Allah's Messenger (ﷺ) said, "If anyone of you feels drowsy while praying he should go to bed (sleep) till his slumber is over because in praying while drowsy one does not know whether one is asking for forgiveness or for a bad thing for oneself."

Sahih al-Bukhari Book 4, Hadith 78 Next Hadith → Anas said, "The Prophet (ﷺ) used to perform ablution for every prayer." I asked Anas, "What did you used to do?' Anas replied, "We used to pray with the same ablution until we break it with Hadath."

Sahih al-Bukhari Book 4, Hadith 80