Charles Ellicott Commentary 2 Corinthians 9:3

"But I have sent the brethren, that our glorying on your behalf may not be made void in this respect; that, even as I said, ye may be prepared:" — 2 Corinthians 9:3 (ASV)

Yet have I sent the brethren . . .—This, then, was his purpose in the new mission. He wanted the performance not to fall short of the promise. They must be found ready, their money collected (Compare to 1 Corinthians 16:2).

In this behalf.—Perhaps, in this particular, or, in this respect, would be more in harmony with modern English phraseology.