Recite (the Surah) 'Say, O you disbelievers!' and then go to sleep at its end, for it is a declaration of freedom from polytheism. (Using translation from Abū Dāʾūd 5055)
"اقْرَأ: {قُلْ يَا أَيُّهَا الْكَافِرُونَ}، ثُمَّ نَمْ عَلَى خَاتمتها، فإِنَّها براءة مِن الشرك".