Musnad Ahmad 25:516

Ya'qub narrated to us, my father narrated to us, from Salih, who said: Ibn Shihab said: Abdullah ibn Ka'b ibn Malik informed me that Ibn Abbas informed him that Ali ibn Abi Talib came out from the presence of the Messenger of Allah, may Allah bless him and grant him peace, during his illness in which he passed away. The people said: "O Abu al-Hasan, how is the Messenger of Allah, may Allah bless him and grant him peace, this morning?" He said: "He is, by the praise of Allah, recovering." Ibn Abbas said: Then Abbas ibn Abd al-Muttalib took him by the hand and said: "Do you not see? By Allah, the Messenger of Allah, may Allah bless him and grant him peace, will pass away in this illness of his. I recognize the faces of the sons of Abd al-Muttalib at the time of death. So come with us to the Messenger of Allah, may Allah bless him and grant him peace, so that we may ask him who this matter belongs to. If it is in us, we will know that, and if it is in others, we will speak to him so that he may recommend us." Ali said: "By Allah, if we ask the Messenger of Allah, may Allah bless him and grant him peace, for it and he denies us, the people will never give it to us. By Allah, I will never ask him for it."