When drowsy, sleep

A person too sleepy to know what he says should sleep, then pray.

Narrated by Aishah

When one of you feels drowsy while praying, let him sleep until his sleepiness leaves him, for if one of you prays while drowsy, he may not know whether he is asking for forgiveness or cursing himself.

Sahih al-Bukhari 212, Sahih Muslim 786

What this hadith teaches

This is about voluntary night prayer: worship is meant to be done with an awake mind, not as a burden.

Reference and grade

Grade
Sahih: agreed upon by al-Bukhari and Muslim
Narrator
Aishah

The hadith in Arabic نص الحديث

إِذَا نَعَسَ أَحَدُكُمْ وَهُوَ يُصَلِّي فَلْيَرْقُدْ حَتَّى يَذْهَبَ عَنْهُ النَّوْمُ، فَإِنَّ أَحَدَكُمْ إِذَا صَلَّى وَهُوَ نَاعِسٌ لاَ يَدْرِي لَعَلَّهُ يَسْتَغْفِرُ فَيَسُبَّ نَفْسَهُ

Arabic text of Sahih al-Bukhari 212, as given on sunnah.com.