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)   

أَنَّ رَسُولَ اللهِ ﷺ قَالَ مَا مِنِ امْرِئٍ تَكُونُ لَهُ صَلَاةٌ بِلَيْلٍ فَيَغْلِبُهُ عَلَيْهَا نَوْمٌ إِلَّا كَتَبَ اللهُ لَهُ أَجْرَ صَلَاتِهِ وَكَانَ نَوْمُهُ صَدَقَةً عَلَيْهِ  

[Machine] The Prophet ﷺ said: "Whoever goes to sleep with the intention of waking up to pray at night, but his eyes overcome him until he wakes up in the morning, it will be written for him as if he performed his intended prayer, and his sleep will be considered a charity from his Lord." And Abu Abdullah al-Hafiz informed us, narrated by Abu Bakr ibn Ishaq, narrated by Muhammad ibn Ahmad ibn al-Nadr, narrated by Mu'awiya ibn Amr, narrated by Zaidah, mentioning it through his chain from the words of Abu Darda. It was also narrated by Jarir from Sulayman al-A'mash, from Habib, from Abdullah ibn Abi Lubabah, from Zirr ibn Hubaysh, from Abu Darda, with a similar narration. And Ath-Thawri narrated it from Abdullah, from Zirr or Suwayd, from Abu Darda, with a chain of narrators indicating it was a statement made by Abu Darda.  

النَّبِيَّ ﷺ قَالَ مَنْ أَتَى فِرَاشَهُ وَهُوَ يَنْوِي أَنْ يَقُومَ يُصَلِّي بِاللَّيْلِ فَغَلَبَتْهُ عَيْنُهُ حَتَّى يُصْبِحَ كُتِبَ لَهُ مَا نَوَى وَكَانَ نَوْمُهُ صَدَقَةً عَلَيْهِ مِنْ رَبِّهِ 4725 وَأَخْبَرَنَا أَبُو عَبْدِ اللهِ الْحَافِظُ ثنا أَبُو بَكْرِ بْنُ إِسْحَاقَ ثنا مُحَمَّدُ بْنُ أَحْمَدَ بْنِ النَّضْرِ ثنا مُعَاوِيَةُ بْنُ عَمْرٍو ثنا زَائِدَةُ فَذَكَرَهُ بِإِسْنَادِهِ مِنْ قَوْلِ أَبِي الدَّرْدَاءِ وَرَوَاهُ جَرِيرٌ عَنْ سُلَيْمَانَ الْأَعْمَشِ عَنْ حَبِيبٍ عَنْ عَبْدَةَ بْنِ أَبِي لُبَابَةَ عَنْ زِرِّ بْنِ حُبَيْشٍ عَنْ أَبِي الدَّرْدَاءِ مَوْقُوفًا وَرَوَاهُ الثَّوْرِيُّ عَنْ عَبْدَةَ عَنْ زِرٍّ أَوْ عَنْ سُوَيْدٍ عَنْ أَبِي الدَّرْدَاءِ أَوْ عَنْ أَبِي ذَرٍّ مَوْقُوفًا