It is narrated from Hazrat Naufal Ashja'i (may Allah be pleased with him) that the Holy Prophet (peace and blessings be upon him) entrusted the daughter of Hazrat Umm Salamah (may Allah be pleased with her) to me and said, "Her upbringing is your responsibility on my behalf." After some time, I again presented myself before the Holy Prophet (peace and blessings be upon him), and he asked me, "What happened to that girl?" I replied, "She is with her mother." The Holy Prophet (peace and blessings be upon him) asked, "What brings you here?" I said, "Please teach me a supplication that I may recite when I go to sleep." The Holy Prophet (peace and blessings be upon him) said, "Recite Surah Al-Kafirun, and go to sleep while reciting its last verse, for this is a declaration of disassociation from shirk (polytheism)."