From his uncle Ubaydullah bin Kaab, who used to guide Kaab after he lost his eyesight and was the most knowledgeable of his people and the one who best preserved the hadiths of the companions of the Messenger of Allah ﷺ, he said, I heard my father Kaab bin Malik, one of the three whose repentance was accepted, narrating that he never stayed behind from any expedition the Messenger of Allah ﷺ led except for two expeditions. He continued the hadith and said in it, "The Messenger of Allah ﷺ set out on this expedition with a great many people, more than ten thousand, and no written register kept track of them all."
و حدثني سلمة بن شبيب حدثنا الحسن بن أعين حدثنا معقل وهو ابن عبيد الله عن الزهري
عن عمه عبيد الله بن كعب وكان قائد كعب حين أصيب بصره وكان أعلم قومه وأوعاهم لأحاديث أصحاب رسول الله ﷺ قال سمعت أبي كعب بن مالك وهو أحد الثلاثة الذين تيب عليهم يحدث أنه لم يتخلف عن رسول الله ﷺ في غزوة غزاها قط غير غزوتين وساق الحديث وقال فيه وغزا رسول الله ﷺ بناس كثير يزيدون على عشرة آلاف ولا يجمعهم ديوان حافظ