Sahih al-Bukhari 4784
Prophetic Commentary on the Qur'an (Tafseer of the Prophet (pbuh))
"Of them, some have fulfilled their obligations (i.e ., have been martyred) and some of them are still waiting, but they have never changed (i.e., they never proved treacherous to their covenant which they concluded with Allah) in the least." (V.33:23)
Narrated Zaid bin Thabit: When we collected the fragramentary manuscripts of the Qur'an into copies, I missed one of the Verses of Surat al-Ahzab which I used to hear Allah's Messenger (ﷺ) reading. Finally I did not find it with anybody except Khuza`ima Al-Ansari, whose witness was considered by Allah's Messenger (ﷺ) equal to the witness of two men. (And that Verse was:) 'Among the believers are men who have been true to their covenant with Allah.'