A.T. Robertson Commentary 1 Corinthians 9:2

"If to others I am not an apostle, yet at least I am to you; for the seal of mine apostleship are ye in the Lord." — 1 Corinthians 9:2 (ASV)

Yet at least I am to you (αλλα γε υμιν ειμ). An argumentum ad hominem and a pointed appeal for their support. Note use of αλλα γε in the apodosis (cf. 8:6).