Contradiction with Matthew 16:21
This verse states that Jesus began to show his disciples that he must go to Jerusalem and suffer many things, which is a straightforward revelation, while Luke 18:31 describes the disciples not understanding what was about to happen.
Matthew 16:21: From that time forth began Jesus to shew unto his disciples, how that he must go unto Jerusalem, and suffer many things of the elders and chief priests and scribes, and be killed, and be raised again the third day.
Contradiction with Mark 9:31
This verse indicates that Jesus was teaching his disciples about his death and resurrection, suggesting they should have understood, whereas Luke 18:31 implies they did not comprehend.
Mark 9:31: For he taught his disciples, and said unto them, The Son of man is delivered into the hands of men, and they shall kill him; and after that he is killed, he shall rise the third day.
Contradiction with John 12:16
This verse suggests that the disciples did not understand these things at first but later remembered, which contrasts with Luke 18:31 where the meaning is hidden from them during the moment.
John 12:16: These things understood not his disciples at the first: but when Jesus was glorified, then remembered they that these things were written of him, and [that] they had done these things unto him.
Contradiction with Luke 9:45
This verse reiterates that the saying was hidden from the disciples so that they did not perceive it, reinforcing their lack of understanding in Luke 18:31.
Luke 9:45: But they understood not this saying, and it was hid from them, that they perceived it not: and they feared to ask him of that saying.