The Companions of Allâh’s Messenger – peace and blessings be upon him – used to say to each other when they met on ‘Eid:

Eid greeting

(taqabbalallâhu minnâ wa minkum, which means ‘may Allâh accept from us and you [our fasts and deeds].’)

Al-Hâfidh Ibn Hajr, Fath Al-Bârî, grades this narration’s chain of transmission hasan and cites it from Al-Mahâmilîyyât.