The surprise expressed by the righteous is genuine; they are astonished. Though they do not doubt Christ’s words, the idea that they have personally ministered to him is so far from their minds that they cannot see how it can be true.
Just as the Lord sees our sins more clearly than we do, so too he sees those acts of righteousness that he has worked in us with greater clarity. Though he is the eternal Son of God and far beyond our capacity to help or to give anything to, by taking human flesh he has put himself in a position in which we can show him personal acts of kindness which we might show to one another. The Lord is not slow to express his appreciation for these. And yet the righteous are perplexed at his words.