{Nor was I taught it} (oute edidachth(886e)). He did not
receive it "from man" (para anthr(9370)(936e), which shuts out both
apo and dia of verse  1 ), whether Peter or any other
apostle, nor was he taught it in the school of Gamaliel in
Jerusalem or at the University of Tarsus. He "received" his
gospel in one way, "through revelation of Jesus Christ" (di'
apokalupse(9373) I(8873)ou Christou). He used parelabon in  1Co 15:3 
about the reception of his message from Christ. It is not
necessary to say that he had only one (because of the aorist
active parelabon, from paralamban(935c), for it can very well be
constative aorist) revelation (unveiling) from Christ. In fact,
we know that he had numerous visions of Christ and in  1Co 11:23 
he expressly says concerning the origin of the Lord's Supper: "I
received (parelabon, again) from the Lord." The Lord Jesus
revealed his will to Paul.