Drowsiness during prayer

عَنْ أَنَسٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ: ’’إِذَا نَعَسَ أَحَدُكُمْ فِي الصَّلاَةِ فَلْيَنَمْ حَتَّى يَعْلَمَ مَا يَقْرَأُ‘‘‏‏.‏

Hazrat Anas^ra narrated, “The Prophet^sa said, ‘When any one of you becomes drowsy in prayer, let him lie down and sleep until he is aware of what he is reciting.’”

(Sahih al-Bukhari, Kitab al-wudu, Bab al-wudu’i mina n-nawmi wa mun lum yara mina n-na‘sati wa n-na‘satayni awi l-khafqati wudu’an, Hadith 213)