ἐπάρχομαι

From LSJ

τὰν ἐπὶ τᾶς → Either with this or on this | Come back victorious or dead

Plutarch, Moralia, 241

English (Autenrieth)

aor. imp. ἐπαρξάσθω, part. -ξάμενος: ritualistic word, always w. δεπάεσσιν, make a beginning (thereto), ‘perform the dedicatory rites’ with the cups, by filling them to pour the libation, Il. 1.471, Od. 3.340.