Matthew Henry Commentary 2 Corinthians 10:12-18

"For we are not bold to number or compare ourselves with certain of them that commend themselves: but they themselves, measuring themselves by themselves, and comparing themselves with themselves, are without understanding. But we will not glory beyond [our] measure, but according to the measure of the province which God apportioned to us as a measure, to reach even unto you. For we stretch not ourselves overmuch, as though we reached not unto you: for we came even as far as unto you in the gospel of Christ: not glorying beyond [our] measure, [that is,] in other men`s labors; but having hope that, as your faith groweth, we shall be magnified in you according to our province unto [further] abundance, so as to preach the gospel even unto the parts beyond you, [and] not to glory in another`s province in regard of things ready to our hand. But he that glorieth, let him glory in the Lord. For not he that commendeth himself is approved, but whom the Lord commendeth." — 2 Corinthians 10:12-18 (ASV)

If we were to compare ourselves with others who excel us, this would be a good method to keep us humble. The apostle establishes a good rule for his conduct: namely, not to boast of things beyond his measure, which was the measure God had distributed to him.

There is no more fruitful source of error than to judge people and opinions by our own prejudices. How common it is for people to judge their own religious character by the opinions and maxims of the world around them! But how different is the rule of God's word!

And of all flattery, self-flattery is the worst. Therefore, instead of praising ourselves, we should strive to approve ourselves to God. In short, let us glory in the Lord our salvation, and in all other things only as evidences of his love, or means of promoting his glory. Instead of praising ourselves or seeking the praise of men, let us desire that honor which comes from God only.