Augustine of Hippo — on Gal 1:1 (EPISTLE TO THE GALATIANS 2)

“The one sent "from men" is a liar; the one sent "through man" tells the truth, as God too, who is truthful, may send truth through men. The one, therefore, who is sent not from men or through man but "through God" derives his truthfulness from the One who makes truthful even those sent through men.”