Umar bin Khattab reported,

There was a man from the Ansar with whom I had an arrangement. Whenever he was absent from the Messenger of Allah ﷺ and I was present, I would bring him whatever had occurred from the Messenger of Allah ﷺ. And whenever I was absent and he was present with the Messenger of Allah ﷺ, he would bring me whatever had occurred from the Messenger of Allah ﷺ.

Bukhari 7256

Sahih

حدثنا سليمان بن حرب حدثنا حماد بن زيد عن يحيى بن سعيد عن عبيد بن حنين عن ابن عباس

عن عمر رضي الله عنهم قال

وكان رجل من الأنصار إذا غاب عن رسول الله ﷺ وشهدته أتيته بما يكون من رسول الله ﷺ وإذا غبت عن رسول الله ﷺ وشهده أتاني بما يكون من رسول الله ﷺ

البخاري 7256صحيح
Contents
Reference
Commentary
Ayat
Collection
Sahih Bukhari
Book
Reports of single narrators
Chapter
Acceptance of the report of a single truthful narrator regarding adhan, prayer, fasting, obligations, and rulings
Numbering
Darussalam 7256
Bukhari 7256