It is narrated from Hazrat Sulaiman bin Surad (may Allah be pleased with him) with reference to Ubayy bin Ka'b (may Allah be pleased with him) that I heard a man reciting the Qur'an. I asked him, "Who taught you this verse?" He replied, "The Prophet Muhammad (peace and blessings be upon him) taught me this verse." I took him to the service of the Prophet Muhammad (peace and blessings be upon him) and said, "O Messenger of Allah! Did you not teach me such and such verse in this way?" The Prophet Muhammad (peace and blessings be upon him) said, "Why not?" I said, "This person claims that you taught him this same verse in another way?" The Prophet Muhammad (peace and blessings be upon him) struck his hand on my chest and prayed, "O Allah, remove doubt from Ubayy," after which all doubts were removed and I never had such doubts again. Then the Prophet Muhammad (peace and blessings be upon him) said, "Jibreel (peace be upon him) and Mika'il (peace be upon him) came to me. Jibreel (peace be upon him) said, 'Recite the Qur'an on one letter.' Mika'il (peace be upon him) said, 'Request an increase from them.' Jibreel (peace be upon him) said, 'Recite it on two letters.' Mika'il (peace be upon him) again said, 'Request an increase from them,' until it reached seven letters." And he said, "Each of them is sufficient and complete."