Sayyiduna Abbad bin Akhdar (may Allah be pleased with him) (or perhaps Ahmar) narrates: When the Prophet (peace and blessings be upon him) went to bed, he would recite Surah al-Kafirun, and he would recite this surah in full.
Al-Tabarani recorded it; its chain contains a narrator, Yahya al-Himmani, and a narrator, Jabir al-Ju'fi, and both of them are da'if (weak).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الأذكار / 17032