The Messenger of Allah ﷺ said, "Let those present convey this to those who are absent."
قال رسول الله ﷺ: ألا ليبلغ الشاهد الغائب.
No references are available.
Ibn Majah (234) narrated it through multiple routes from Bahz bin Hakeem, from his father, from his grandfather Muawiya Qushayri, and he related the hadith. Its isnad is hasan because of Bahz, who is the son of Hakeem bin Muawiya bin Hayda Qushayri, and his father is Hakeem bin Muawiya, both of whom are hasan al-hadith.