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. (Using translation from Abū Dāʾūd 1314)
عَنِ النَّبِيِّ ﷺ قَالَ مَا مِنَ امْرِئٍ يَكُونُ لَهُ صَلَاةٌ مِنَ اللَّيْلِ يَغْلِبُهُ عَلَيْهَا نَوْمٌ إِلَّا كَانَ نَوْمُهُ عَلَيْهِ صَدَقَةً وَكُتِبَ لَهُ أَجْرُ صَلَاتِهِ