Albert Barnes Commentary Luke 24:25

"And he said unto them, O foolish men, and slow of heart to believe in all that the prophets have spoken!" — Luke 24:25 (ASV)

O fools. The word fool is sometimes a term of reproach denoting wickedness. In this sense, we are forbidden to use it in addressing another (Matthew 5:22). However, that is a different word in the Greek from the one that occurs here.

The one used there implies contempt, but the one used in this place denotes weakness or dullness. He reproached them for not seeing what he himself had so clearly predicted, and what had been foretold by the prophets.

The word used in the original does not imply as much reproach as the word fool does among us. It was not an expression of contempt; it was an expression denoting merely that they were thoughtless and did not properly attend to the evidence that he must die and rise again.

Slow of heart to believe. Not quick to perceive. Dull of learning. They had allowed their previous opinions and prejudices to prevent their seeing the evidence that he must die and rise from the dead.

All that the prophets have spoken. Respecting the character and sufferings of the Messiah. See Barnes on Luke 24:27.