Sunan Abi Dawud 5055
Farwah b. Nawfal quoted his father as saying that the Prophet (ﷺ) said to Nawfal (his father):
Recite (the Surah) 'Say, O you disbelievers!' and then go to sleep at its end, for it is a declaration of freedom from polytheism.
حَدَّثَنَا النُّفَيْلِيُّ، حَدَّثَنَا زُهَيْرٌ، حَدَّثَنَا أَبُو إِسْحَاقَ، عَنْ فَرْوَةَ بْنِ نَوْفَلٍ، عَنْ أَبِيهِ، أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ لِنَوْفَلٍ ‏"‏ اقْرَأْ ‏{‏ قُلْ يَا أَيُّهَا الْكَافِرُونَ ‏}‏ ثُمَّ نَمْ عَلَى خَاتِمَتِهَا فَإِنَّهَا بَرَاءَةٌ مِنَ الشِّرْكِ ‏"‏ ‏.‏