Charles Spurgeon Commentary Galatians 2:1-2

"Then after the space of fourteen years I went up again to Jerusalem with Barnabas, taking Titus also with me. And I went up by revelation; and I laid before them the gospel which I preach among the Gentiles but privately before them who were of repute, lest by any means I should be running, or had run, in vain." — Galatians 2:1-2 (ASV)

Then fourteen years after I went up again to Jerusalem with Barnabas, and took Titus with me also. And I went up by revelation.

He was sent by the church at Antioch, but the church there was guided by revelation, so that Paul is correct in saying, I went up by revelation.