وَعَنْ فَرْوَةَ بْنِ نَوْفَلٍ عَنْ أَبِيهِ
أَنَّهُ قَالَ: يَا رَسُولَ اللَّهِ عَلِّمْنِي شَيْئًا أَقُولُهُ إِذَا أَوَيْتُ إِلَى فِرَاشِي. فَقَالَ: «اقْرَأْ (قُلْ يَا أَيُّهَا الْكَافِرُونَ) فَإِنَّهَا بَرَاءَةٌ مِنَ الشِّرْكِ»
Farwa ibn Naufal quoted his father as saying that he had asked God’s messenger to teach him something to say when he went to bed, and was told to recite, “Say, O infidels”, for it is a declaration of freedom from polytheism. Tirmidhi, Abu Dawud and Darimi transmitted it.
Mishkat al-Masabih 2065, Book 9, The Excellent Qualities of the Qur'an, Hadith 51. 1 min read