‘But we will not glory beyond our measure, but according to the measure of the province (boundary, area within boundaries) which God apportioned to us as a measure, to reach even to you.'
Paul on the other hand will not glory beyond measure. He does not need to do so to prop up a failing image. He will not use a measurement suggested by men at all. He will certainly not measure himself against others, hoping that they will return the compliment. He will use God's measurement, a measurement revealed by His mighty work in Corinth through Paul. That had demonstrated that in God's eyes this was Paul's province, the place where had the right to take charge. That is the measure that God has apportioned to him, the province God gave him in which to demonstrate his genuine calling, and in which he succeeded. And that will be his boast. What can they show compared with this?
We can compare here 1Co 4:15; 1 Corinthians 4:19. It was he who by God's power established the church in Corinth. That was the final proof of his authority and power. What had these men done to compare with that? They may have fine words, but where is their power? How many new churches have they founded on virgin territory?
Paul is here claiming that God had a set purpose for him, that He had as it were, allocated certain areas which he was to evangelise. It had, as it were, been measured out to him with a measuring rod, and the Corinthians were within his boundaries, as is demonstrated by his success.