Hazrat Ubayy (ra) is among those esteemed companions who had heard a large part of the ahadith [oral traditions] directly from the Holy Prophet (sa). Many companions studied ahadith from him and in fact, the majority of his students would comprise of companions. (Even the companions would listen to the ahadith from him.) Hazrat Umar (ra) bin Khattab, Hazrat Abu Ayub Ansari (ra), Hazrat Ubadah bin Samit (ra), Hazrat Abu Hurairah (ra), Hazrat Abu Musa Ash‘ari (ra), Hazrat Anas bin Malik (ra), Hazrat Abdullah bin Abbas (ra), Hazrat Sahl bin Saad (ra) and Hazrat Suleman bin Sard (ra) were among those who benefited from Hazrat Ubayy’s (ra) knowledge of ahadith.
(Sheikh Shah Moinuddin Ahmad Nadvi, Siyar al-Sahabah, Vol. 3 [Karachi, Pakistan: Dar al-Ishaah Urdu Bazar, 2004] 153)