Musnad Ahmad

It is narrated from Imam Sha'bi, may Allah have mercy on him, that once Sayyiduna Umar, may Allah be pleased with him, passed by Sayyiduna Talha, may Allah be pleased with him, and saw him in a distressed state. He said, "Perhaps you are not pleased with the caliphate of your cousin, that is, me?" He replied, "Allah's refuge! I should never do such a thing. The real matter is that I heard the Prophet, peace and blessings be upon him, say: 'I know a word that if a person says it at the time of death, it will make the soul's departure easy for him, and on the Day of Resurrection it will be a source of light for him.' (I regret that I could not ask the Prophet, peace and blessings be upon him, about this word, and the Prophet, peace and blessings be upon him, himself did not mention it. That is why I am distressed.)" Sayyiduna Umar, may Allah be pleased with him, said, "I know that word." (Sayyiduna Abu Talha, may Allah be pleased with him, said 'Alhamdulillah' and asked, "What is that word?") He replied, "It is the same word that the Prophet, peace and blessings be upon him, presented before his uncle, that is, 'La ilaha illallah' (There is no god but Allah)." Sayyiduna Talha, may Allah be pleased with him, said, "You have spoken the truth; you have removed the veil from me. If the Prophet, peace and blessings be upon him, had known any word superior to this, he would have instructed his uncle with it."