Tradition
St. John Chrysostom
Homilies on Second Corinthians
Homily 26 › 2 Corinthians 12:8
3. “Concerning this thing I besought the Lord thrice.”
That is, oftentimes. This also is a mark of great lowliness of mind, his not concealing that he could not bear those insidious plottings, that he fainted under them and was reduced to pray for deliverance.
Source: Homilies on Second Corinthians (New Advent)