Sunan Abi Dawud Book 5, Hadith 65
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.
The Messenger of Allah (ﷺ) as saying: He who misses him daily round of recital or part of it due to sleep and he recites it between the dawn and the noon prayers, will be reckoned as if he recited it at night.
The Messenger of Allah (ﷺ) as saying: Our Lord who is blessed and exalted descends every night to the lowest heaven when the last one-third of the night remains, and says: Who supplicated Me so that I may answer him ? Who asks of Me so that I may give to him ? Who asks My forgiveness so that I may forgive him ?