The Messenger of Allah ﷺ delivered a sermon on the Day of Sacrifice and said, "Let those present convey this to those who are absent, for many a person to whom it is conveyed will retain it better than the one who heard it directly."
خطب رسول الله ﷺ يوم النحر فقال: ليبلغ الشاهد الغائب، فإنه رب مبلغ يبلغه أوعى له من سامع.
Bukhari (67) and Muslim (1679) both narrated it through Ibn Awn, from Ibn Sirin, from Abdul-Rahman bin Abu Bakra, from his father, and he related it. It is an abridgment of a longer hadith that mentions the Prophet'sﷺ sermon on the Day of Sacrifice.