Jamieson, Fausset and Brown on 2 Corinthians 11:5

5. For--My claim is superior to that of the false teachers, "For," &c.

I suppose--I reckon [Alford].

I was not--Greek, "That I have not been, and am not."

the very chiefest apostles--James, Peter, and John, the witnesses of Christ's transfiguration and agony in Gethsemane. Rather, "those overmuch apostles," those surpassers of the apostles in their own esteem. This sense is proved by the fact that the context contains no comparison between him and the apostles, but only between him and the false teachers; 2Co 11:6 also alludes to these, and not to the apostles; compare also the parallel phrase, "false apostles" (see on 2Co 11:13 and 2Co 12:11) [Alford].