He was relating his account of when he had stayed behind from the Messenger of Allah ﷺ during the expedition of Tabuk. He recounted the long hadith, in which he said, when he was given the good news of his repentance being accepted, "I set out toward the Messenger of Allah ﷺ, and the people met me in groups, congratulating me on the acceptance of my repentance, saying, 'May Allah's acceptance of your repentance bring you joy,' until I entered the mosque. Talha bin Ubaydullah rose and hurried over to me, shook my hand, and congratulated me. Not a single man from the Muhajirun stood up for me except him, and I will never forget that of Talha."
يحدث حديثه حين تخلف عن رسول الله ﷺ في غزوة تبوك. فذكر الحديث بطوله. قال فيه لما بشر بالتوبة: انطلقت إلى رسول الله ﷺ فتلقاني الناس فوجا فوجا يهنئونني بالتوبة، يقولون: لتهنئك توبة الله عليك حتى دخلت المسجد، فقام إلي طلحة بن عبيد الله يهرول حتى صافحني وهنأني، ما قام إلي رجل من المهاجرين غيره، ولا أنساها لطلحة.
Bukhari (4418) and Muslim (2769) both narrated it through Ibn Shihab, from Abdul-Rahman bin Abdullah bin Kaab bin Malik, that Abdullah bin Kaab, who guided Kaab when he went blind, among his sons, said, "I heard Kaab bin Malik," and he related the hadith.