Sayyiduna Zayd bin Thabit (may Allah be pleased with him) said: When we wrote the copies of the Qur'an (mushafs), I could not find a verse that I used to hear from the Messenger of Allah (peace and blessings be upon him), and I found that verse with Khuzaymah bin Thabit al-Ansari (may Allah be pleased with him): "Among the believers are men who have been true to the covenant they made with Allah; among them is he who has fulfilled his vow, and among them is he who is waiting, and they have not altered it in the least" [Surah al-Ahzab: 23]. Zayd (may Allah be pleased with him) said: And Khuzaymah (may Allah be pleased with him) used to be called Dhu al-Shahadatayn (the one with two testimonies).
Hadith Referenceالمعجم الكبير للطبراني / باب الزاي / 4822