Musnad Ahmad 175:27

Hajjaj narrated to us, he said: Layth ibn Sa’d narrated to us, he said: ‘Uqayl ibn Khalid narrated to me, from Ibn Shihab, that he said: ‘Abd al-Rahman ibn ‘Abd Allah ibn Ka’b ibn Malik informed me, that ‘Abd Allah ibn Ka’b ibn Malik—and he was the guide for Ka’b from among his sons when he became blind—said: I heard Ka’b ibn Malik narrating his story when he stayed behind from the Messenger of Allah (may Allah bless him and grant him peace) in the Battle of Tabuk. Ka’b ibn Malik said: I never stayed behind from the Messenger of Allah (may Allah bless him and grant him peace) in any battle he fought except in the Battle of Tabuk, other than that I had stayed behind from the Battle of Badr, and he did not reproach anyone who stayed behind from it, because the Messenger of Allah (may Allah bless him and grant him peace) had only gone out intending the caravan that belonged to Quraysh, in which was Abu Sufyan ibn Harb and a group of Quraysh. Then he said: "Come." So I came walking until I sat before him. He said: "What kept you behind? Had you not purchased your mount?" I said: "Yes, O Messenger of Allah. By Allah, if I had sat before someone other than you from the people of the world, I would have seen that I would exit his anger with an excuse, and I have been given eloquence." Then he mentioned the hadith, and said in it: "I truly hope for the pardon of Allah." And he said: I said to my wife: "Join your family, and be with them until Allah decides in this matter." And he said: I heard the voice of a crier who ascended the highest part of Mount Sal’, at the top of his voice: "O Ka’b ibn Malik, rejoice!" He said: So I fell down prostrating, and I knew that relief had come. And the Messenger of Allah (may Allah bless him and grant him peace) announced to the people our repentance when he prayed the dawn prayer. Then he mentioned the meaning of the hadith of the nephew of Ibn Shihab, and said in it: So I say to myself: Did he move his lips in returning the greeting?