A.T. Robertson Commentary 2 Corinthians 8:19

"and not only so, but who was also appointed by the churches to travel with us in [the matter of] this grace, which is ministered by us to the glory of the Lord, and [to show] our readiness:" — 2 Corinthians 8:19 (ASV)

But who was also appointed (αλλα κα χειροτονηθεις). Anacoluthon. The first aorist passive participle χειροτονηθεις is from χειροτονεω, old verb to stretch out the hands (χειρ τεινω) and so to vote in public. The idea is that this brother was chosen by the churches, not by Paul. Only here in N.T. save Ac 14:23 where it means to appoint without notion of raising the hands. In Ac 10:41 we have προχειροτονεω.

To travel with us (συνεκδημος). Late word for travelling companion. So in the inscriptions (συν, together with, εκδημος, away from home).