It is narrated from Sayyiduna Jabalah bin Harithah (may Allah be pleased with him) that he said: "I said to the Messenger of Allah (peace and blessings be upon him): Teach me something that will benefit me. He (peace and blessings be upon him) said: 'When you lie down on your bed, recite "Say: O disbelievers" (Surah al-Kafirun), for it is a declaration of freedom from shirk.'"
No one narrated this hadith from Abu Ishaq (may Allah have mercy on him), from Farwah (may Allah have mercy on him), from Sayyiduna Jabalah (may Allah be pleased with him), except Sharik (may Allah have mercy on him).
Hadith Referenceالمعجم الأوسط / باب الألف / 888
Hadith Takhrij«أخرجه النسائي فى «السنن الكبرى» برقم: 10568، وأحمد فى «مسنده» برقم: 24420، 24421، والطبراني فى «الكبير» برقم: 2195، والطبراني فى «الأوسط» برقم: 1968»