It is reported about Sayyiduna Imran bin Husayn (may Allah be pleased with him) that he said: "Shall I not narrate to you a hadith which, ever since I heard it from the Prophet (peace and blessings be upon him), I have not narrated to anyone, out of fear that people would rely on it alone? I heard the Prophet (peace and blessings be upon him) say: 'Whoever knows with the certainty of his heart that Allah Almighty is his Lord and that I am His Prophet' (the narrator said: The Prophet (peace and blessings be upon him) said this while pointing to his skin) 'Allah Almighty will make that person forbidden to Hell.'"
Imam al-Bazzar recorded it. Its chain contains a narrator, Imran al-Qasir, who is matruk (abandoned), and another narrator, Abdullah bin Abi al-Qalus.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الإيمان / 36