When the scrolls were copied into the official codices, I noticed that one verse from Surah al-Ahzab was missing. I had heard the Messenger of Allah ﷺ reciting it, yet I could not find it with anyone except Khuzayma bin Thabit al-Ansari, the one whose testimony the Messenger of Allah ﷺ had declared equal to the testimony of two men. The verse was, "Among the believers are men who have been true to the covenant they made with Allah" [Ahzab 33:23].
نسخت الصحف في المصاحف، ففقدت آية من سورة الأحزاب، كنت أسمع رسول الله ﷺ يقرأ بها، فلم أجدها إلا مع خزيمة بن ثابت الأنصاري الذي جعل رسول الله ﷺ شهادته شهادة رجلين، وهو قوله: {من المؤمنين رجال صدقوا ما عهدوا الله عليه} [الأحزاب: ٢٣].
Bukhari reported it in the Book of Jihad and Military Expeditions (2807) through several routes from Zuhri, from Kharija bin Zayd, that Zayd bin Thabit said, and then he related it.The reason his testimony was counted as the testimony of two men is mentioned in the following hadith.