Sahih al-Bukhari 4988
Sahih al-Bukhari · Book 66: Virtues of the Qur'an · The collection of the Qur'an
Zaid bin Thabit added, "A verse from Surat Ahzab was missed by me when we copied the Qur'an and I used to hear Allah's Messenger (ﷺ) reciting it. So we searched for it and found it with Khuza`ima bin Thabit Al-Ansari. (That Verse was):
قَالَ ابْنُ شِهَابٍ وَأَخْبَرَنِي خَارِجَةُ بْنُ زَيْدِ بْنِ ثَابِتٍ ، سَمِعَ زَيْدَ بْنَ ثَابِتٍ ، قَالَ فَقَدْتُ آيَةً مِنَ الأَحْزَابِ حِينَ نَسَخْنَا الْمُصْحَفَ قَدْ كُنْتُ أَسْمَعُ رَسُولَ اللَّهِ صلى الله عليه وسلم يَقْرَأُ بِهَا فَالْتَمَسْنَاهَا فَوَجَدْنَاهَا مَعَ خُزَيْمَةَ بْنِ ثَابِتٍ الأَنْصَارِيِّ {مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللَّهَ عَلَيْهِ} فَأَلْحَقْنَاهَا فِي سُورَتِهَا فِي الْمُصْحَفِ.
'Among the Believers are men who have been true in their covenant with Allah.' (33.23)