Qays bin Abi Hazim قيس بن أبي حازم · The Book of the Sunnah

"We were with the Prophet (ﷺ), and we were strong youths, so we learned faith before we learned Qur'an. Then we learned Qur'an and our faith increased thereby."

"I heard Sa'eed bin Musayyab say: 'Sa'd bin Abu Waqqas said: 'No one else became Muslim on the same day as I did; for seven days I was one-third of Islam.'"