Mukhtasar Muslim

Jabir bin Abdullah (may Allah be pleased with him) says: I sought permission from the Prophet (peace and blessings of Allah be upon him), so the Prophet (peace and blessings of Allah be upon him) asked, "Who is it?" I replied, "It is I." The Prophet (peace and blessings of Allah be upon him) said, "'It is I, it is I.'" In another narration, it is as if the Prophet (peace and blessings of Allah be upon him) disliked saying "It is I."