Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) said: "Glorified is Allah Almighty, free of every flaw! What is it that is coming towards you, and what is it that you are about to receive?" He said this three times. Then Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: "Has some revelation come down, or is an enemy approaching?" The Prophet (peace and blessings be upon him) said: "Indeed, Allah Almighty forgives all the people of this qiblah on the first night of the month of Ramadan." The narrator states: A man who was present before him said, shaking his head: "Excellent, excellent!" The Prophet (peace and blessings be upon him) said: "Perhaps you are troubled by something?" He said: "No, but I thought of a hypocrite." The Prophet (peace and blessings be upon him) said: "The hypocrite is a disbeliever, and the disbeliever gets nothing of that."
Al-Tabarani recorded it in al-Mu'jam al-Awsat. Its chain contains a narrator, Khalaf Abu al-Rabi', and I have not found anyone narrating from him other than Amr bin Hamzah, as Ibn Abi Hatim mentioned.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصيام / 4790