25 He said to them, “Foolish men, and slow of heart to believe in all that the prophets have spoken!
Luke 24:25 Cross References - WEB
Mark 7:18
18 He said to them, “Are you also without understanding? Don’t you perceive that whatever goes into the man from outside can’t defile him,
Mark 8:17-18
Mark 9:19
19 He answered him, “Unbelieving generation, how long shall I be with you? How long shall I bear with you? Bring him to me.”
Mark 16:14
14 Afterward he was revealed to the eleven themselves as they sat at the table, and he rebuked them for their unbelief and hardness of heart, because they didn’t believe those who had seen him after he had risen.
Hebrews 5:11-12
11 About him we have many words to say, and hard to interpret, seeing you have become dull of hearing.
12 For although by this time you should be teachers, you again need to have someone teach you the rudiments of the first principles of the revelations of God. You have come to need milk, and not solid food.