ἐκστρατεύειν

From LSJ

τί ἦ μοι ταῦτα περὶ δρῦν ἢ περὶ πέτρην → but what is this to me, about an oak or a rock | but what are these things about a tree or a rock to me | why all this about trees and rocks | why all this about what we have nothing to do with | but why am I off on this tangent

Source

Greek > English (Woodhouse Verbs Reversed)

(see also ἐκστρατεύω): go on a campaign, go on an expedition, take the field

Lexicon Thucydideum

in expeditionem exire, to go out on an expedition, 5.54.1, 5.55.3, 5.58.1. 5.76.1.
MED. idem, the same 2.12.2, 3.102.7, 3.105.1, 5.55.4.