Ignatius of Antioch, Epistle to the Philadelphians 5.4
Make every effort, then, to share in one Eucharist. For there is one flesh of our Lord Jesus Christ and one cup that unites us in his blood, one altar, just as there is one bishop together with the council of elders and the deacons, my fellow servants. Do this so that whatever you do, you may act according to God.
Greek
Σπουδάσατε οὖν μιᾷ εὐχαριστίᾳ χρῆσθαι: μία γὰρ σὰρξ τοῦ κυρίου ἡμῶν Ἰησοῦ Χριστοῦ καὶ ἓν ποτήριον εἰς ἕνωσιν τοῦ αἵματος αὐτοῦ, ἓν θυσιαστήριον, ὡς εἷς ἐπίσκοπος ἅμα τῷ πρεσβυτερίῳ καὶ διακόνοις τοῖς συνδούλοις μου: ἵνα, ὃ ἐὰν πράσσητε, κατὰ θεὸν πράσσητε.