When we wrote the Holy Qur'an, I missed one of the Verses of Surat-al-Ahzab which I used to hear Messenger of Allah ﷺ reciting. Then we searched for it and found it with Khuzaʿima bin Thabit Al-Ansari. The Verse was:-- 'Among the Believers are men Who have been true to Their Covenant with Allah, Of them, some have fulfilled Their obligations to Allah (i.e. they have been Killed in Allah's Cause), And some of them are (still) waiting" (33.23) So we wrote this in its place in the Qur'an.  

أَسْمَعُ رَسُولَ اللَّهِ ﷺ يَقْرَأُ بِهَا فَالْتَمَسْنَاهَا فَوَجَدْنَاهَا مَعَ خُزَيْمَةَ بْنِ ثَابِتٍ الأَنْصَارِيِّ {مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللَّهَ عَلَيْهِ فَمِنْهُمْ مَنْ قَضَى نَحْبَهُ وَمِنْهُمْ مَنْ يَنْتَظِرُ } فَأَلْحَقْنَاهَا فِي سُورَتِهَا فِي الْمُصْحَفِ  

[Machine] Zaid, when we wrote the copies of the Quran, I lost a verse that I used to hear from the Messenger of Allah ﷺ . I found it with Khuzaimah bin Thabit al-Ansari, who was called "the one with the two testimonies." The verse is: "Among the believers are men who have been true to their covenant with Allah. Some of them have fulfilled their vow, and some are still waiting, but they have not changed (their commitment) in the least."  

زَيْدٌ لَمَّا كَتَبْنَا الْمَصَاحِفَ فَقَدْتُ آيَةً كُنْتُ أَسْمَعُهَا مِنْ رَسُولِ اللهِ ﷺ فَوَجَدْتُهَا عِنْدَ خُزَيْمَةَ بْنِ ثَابِتٍ الْأَنْصَارِيِّ {مِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللهَ عَلَيْهِ فَمِنْهُمْ مَنْ قَضَى نَحْبَهُ وَمِنْهُمْ مَنْ يَنْتَظِرُ وَمَا بَدَّلُوا تَبْدِيلًا} قَالَ «وَكَانَ خُزَيْمَةُ يُدْعَى ذَا الشَّهَادَتَيْنِ»