The King had just thanked them for feeding Him, giving Him drink, and taking Him in (Matthew 25:35-36). They could not remember ever doing that for Him. Gill says they answer "with wonder and astonishment," partly because they seem to take His words as if these things were done to Him in person, though "the far greater part of them had never seen him in the flesh," and partly from surprise that He would notice such small acts. He adds that they had forgotten their own kindnesses, "their left hand not knowing what their right hand had done." Barnes calls the answer "indicative of humility," a deep sense of being unworthy of such praise. He adds that it is not to be supposed the righteous will actually say these words at the judgment; the question is "a proper expression of their feelings."

The King answers them plainly: "Verily I say unto you, Inasmuch as ye have done it unto one of the least of these my brethren, ye have done it unto me" (Matthew 25:40). They had not seen Him hungry, but they had seen His brethren hungry and fed them. The scene ends with "the righteous into life eternal" (Matthew 25:46).

"An hungred" is older English for "hungry." The Greek peinonta means hungering, and "fed" is ethrepsamen, we fed. The questions of the righteous in Matthew 25:37-39 walk back through the same six needs the King had just named (Matthew 25:35-36): hungry, thirsty, a stranger, naked, sick, and in prison.

Jesus calls those on the right "sheep" (Matthew 25:33). Barnes says the name is given to the righteous because "the sheep is an emblem of innocence and harmlessness." Gill observes that "the far greater part of them had never seen him in the flesh," which is part of why the King's words surprised them.

This question draws out one of the most striking things Jesus says about Himself. The King on the throne of glory counts kindness done to the lowly as kindness done to Him. Barnes explains "the least of these" as "the obscurest, least known, poorest, and most despised and afflicted." He gives two readings of "my brethren": "Either those who are Christians, whom he condescends to call brethren, or those who are afflicted, poor, and persecuted." Either way, the King stands so close to the needy that serving them is serving Him.

The scene does not teach that the kingdom is bought with good deeds. The King tells the righteous to "inherit the kingdom prepared for you from the foundation of the world" (Matthew 25:34). Matthew Henry writes, "We are not to suppose that acts of bounty will entitle to eternal happiness"; their works mark them as believers made holy by the Spirit of Christ. Their surprise is itself telling: they did not know that what they did "unto one of the least of these my brethren" they did unto Him (Matthew 25:40).