Abu Bakr sent for me after the heavy casualties at the Battle of Yamamah, and when I arrived, I found Umar sitting with him.Abu Bakr said, "Zayd bin Thabit, you are a young, intelligent man, and we hold no suspicion against you. You used to write down the revelation for the Messenger of Allah ﷺ, so search out the Quran and gather it together."Zayd said, "By Allah, if they had charged me with moving one of the mountains, it would not have weighed more heavily upon me than what he commanded me to do in collecting the Quran."So I said, "How can the two of you do something that the Messenger of Allah ﷺ himself did not do?"Abu Bakr replied, "By Allah, it is good."Abu Bakr kept pressing the matter with me until Allah opened my heart to it, just as He had opened the hearts of Abu Bakr and Umar .
حدثنا أبو كامل حدثنا إبراهيم بن سعد حدثنا ابن شهاب عن عبيد بن السباق
أرسل إلي أبو بكر مقتل أهل اليمامة فإذا عمر عنده جالس وقال أبو بكر يا زيد بن ثابت إنك غلام شاب عاقل لا نتهمك قد كنت تكتب الوحي لرسول الله ﷺ فتتبع القرآن فاجمعه قال زيد فوالله لو كلفوني نقل جبل من الجبال ما كان أثقل علي مما أمرني به من جمع القرآن فقلت أتفعلان شيئا لم يفعله رسول الله ﷺ قال هو والله خير فلم يزل أبو بكر يراجعني حتى شرح الله صدري بالذي شرح له صدر أبي بكر وعمر رضي الله عنهما
Its isnad is sahih. Ubayd bin Sabbaq was one of the trustworthy Successors, and his hadith is transmitted by the whole group of narrators. The hadith is well known, and the story is well known, and it is found in Bukhari 8/344, no. 4679, Fath al-Bari, in the tafsir of "There has come to you a messenger", and in Tirmidhi 5/283, no. 3103, in the tafsir of Surah Tawbah, where he said, hasan sahih. There are many others besides these two.