(8) باب الْقُرَّاءِ مِنْ أَصْحَابِ النَّبِيِّ صلى الله عليه وسلم
Narrated Shaqiq bin Salama:
Once `Abdullah bin Mas`ud delivered a sermon before us and said, "By Allah, I learnt over seventy Suras direct from Allah's Messenger (ﷺ) . By Allah, the companions of the Prophet (ﷺ) came to know that I am one of those who know Allah's Book best of all of them, yet I am not the best of them." Shaqiq added: I sat in his religious gathering and I did not hear anybody opposing him (in his speech).
Reference: Sahih al-Bukhari 5000
In-book reference: Book 66, Hadith 22
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 6, Book 61, Hadith 522