Abdullah bin Abbas reported,

He asked, "Which of the two recitations do you consider to be the earlier one?"They replied, "The recitation of Abdullah."He said, "No, rather it is the later one. The Quran used to be reviewed with the Messenger of Allah ﷺ once every year, but in the year he passed away it was reviewed with him twice. Abdullah witnessed it and so came to know what had been abrogated and what had been changed."

Ahmad 3422

Sahih

حدثنا يعلى ومحمد المعنى قالا حدثنا الأعمش عن أبي ظبيان

عن ابن عباس قال

أي القراءتين تعدون أول قالوا قراءة عبد الله قال لا بل هي الآخرة كان يعرض القرآن على رسول الله ﷺ في كل عام مرة فلما كان العام الذي قبض فيه عرض عليه مرتين فشهده عبد الله فعلم ما نسخ منه وما بدل

أحمد 3422صحيح
Contents
Reference
Commentary
Ayat
Collection
Musnad Ahmad
Book
Abdullah bin Abbas bin Abdul-Muttalib
Numbering
Darussalam 3422
Ahmad 3422