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): 'Among the Believers are men who have been true in their covenant with Allah.' (33.23)

Narrated Anas:

My uncle Anas bin An-Nadr was absent from the Battle of Badr. He said, "O Allah's Messenger! I was absent from the first battle you fought against the pagans. (By Allah) if Allah gives me a chance to fight the pagans, no doubt. Allah will see how (bravely) I will fight." On the day of Uhud when the Muslims turned their backs and fled, he said, "O Allah! I apologize to You for what these (i.e. his companions) have done, and I denounce what these (i.e. the pagans) have done." Then he advanced and Sa`d bin Mu`adh met him. He said "O Sa`d bin Mu`adh ! By the Lord of An-Nadr, Paradise! I am smelling its aroma coming from before (the mountain of) Uhud," Later on Sa`d said, "O Allah's Apostle! I cannot achieve or do what he (i.e. Anas bin An-Nadr) did. We found more than eighty wounds by swords and arrows on his body. We found him dead and his body was mutilated so badly that none except his sister could recognize him by his fingers." We used to think that the following Verse was revealed concerning him and other men of his sort: "Among the believers are men who have been true to their covenant with Allah.........." (33.23) His sister Ar-Rubbaya' broke a front tooth of a woman and Allah's Messenger (ﷺ) ordered for retaliation. On that Anas (bin An-Nadr) said, "O Allah's Messenger! By Him Who has sent you with the Truth, my sister's tooth shall not be broken." Then the opponents of Anas's sister accepted the compensation and gave up the claim of retaliation. So Allah's Messenger (ﷺ) said, "There are some people amongst Allah's slaves whose oaths are fulfilled by Allah when they take them."

Narrated Kharija bin Zaid:

Zaid bin Thabit said, "When the Qur'an was compiled from various written manuscripts, one of the Verses of Surat Al-Ahzab was missing which I used to hear Allah's Messenger (ﷺ) reciting. I could not find it except with Khuza`ima bin Thabjt Al-Ansari, whose witness Allah's Messenger (ﷺ) regarded as equal to the witness of two men. And the Verse was:-- "Among the believers are men who have been true to what they covenanted with Allah." (33.23)

Narrated Zaid bin Thabit:

When we wrote the Holy Qur'an, I missed one of the Verses of Surat-al-Ahzab which I used to hear Allah's Messenger (ﷺ) reciting. Then we searched for it and found it with Khuza`ima 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.