If any man's work abide which he hath built thereupon, he shall receive a reward. If any man's work abide - Perhaps there is here an allusion to the purifying of different sorts of vessels under the law. All that could stand the fire were to be purified by the fire; and those which could not resist the action of the fire were to be purified by water, Numbers 31:23. The gold, silver, and precious stones, could stand the fire; but the wood, hay, and stubble, must be necessarily consumed. So, in that great and terrible day of the Lord, all false doctrine, as well as the system that was to pass away, should be made sufficiently manifest; and God would then show that the Gospel, and that alone, was that system of doctrine which he should bless and protect, and none other.
He shall receive a reward - He has not only preached the truth, but he has labored in the word and doctrine. And the reward is to be according to the labor. See on 1 Corinthians 3:8 (note).