John Calvin on Luke 24:25-27

This reproof [“O foolish ones, and slow of heart to believe”] appears to be too harsh and severe considering this person’s weakness; but whoever considers all the circumstances will easily understand that the Lord had good reason for rebuking so sharply those on John_Calvinwhom he had long bestowed labor to little purpose, and almost without any fruit. It should be noted that what is said here is not confined to these two, but, as a reproof of a common fault, the rest of their companions should hear it immediately from their mouths. So frequently had Christ forewarned them of his death—so frequently had he discussed the new and spiritual life and confirmed his teaching by prophets’ oracles—it is as if he had spoken among the deaf—rather to sticks and stones! Overpowered with dread at his death they did not know where to turn. This hesitation, therefore, he justly attributes to folly, and he identifies its cause as their torpor that they were not more ready to believe. And he does not only reprove them because they had the best Teacher, were sluggish and slow to learn, but also because they had not listened to the prophets’ words. It is as if he had said that their stupidity is without excuse. It was their own fault—in and of themselves the prophets’ teaching shines radiantly and was correctly explained to them. Similarly today, most people sustain their ignorance through their own fault, because they are unteachable and rigid. But let us note when Christ sees that his disciples are exceedingly sluggish, in order to stir them he begins to scold. Thus we must compel those whom we have found to be stubborn or sluggish.

~Luke, ed. Beth Kreitzer, Reformation Commentary on Scripture, NT Vol. III, p. 485