Sunan Abu Dawud
1314
Sahih+2

Narrated Aisha, Ummul Mu'minin: The Prophet (ﷺ) said: Any person who offers prayer at night regularly but (on a certain night) he is dominated by sleep will be given the reward of praying. His sleep will be almsgiving

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid