He did not want anyone to know it

Many times Jesus Christ spoke about his Crucifixion, But none of them could understand it - Let these words sink into your ears: The Son of Man is about to be delivered into the hands of men. But they (Disciples) did not understand this saying, and it was concealed from them, so that they might not perceive it. And they were afraid to ask him about this saying - Luke 9:44-45

Mark is telling the reason why the Disciples could not understand it, - Then they departed from there and passed through Galilee, and He did not want anyone to know it. For He taught His disciples and said to them, “The Son of Man is being betrayed into the hands of men, and they will kill Him. And after He is killed, He will rise the third day.” But they did not understand this saying, and were afraid to ask Him - Mark 9:30-32

Mark refers crucifixion of Jesus Christ as "passing through Galilee", and Jesus Christ did not want anyone to know about it, which clearly tells that Jesus Christ is God who knows and control everything including our thoughts and understanding. And after the resurrection, the Spirit of God opened their mind to understand the teaching of Jesus Christ.

According to Gospel of Luke

In their fright the women bowed down with their faces to the ground, but the men said to them, “Why do you look for the living among the dead? He is not here; he has risen! Remember how he told you, while he was still with you in Galilee: ‘The Son of Man must be delivered over to the hands of sinners, be crucified and on the third day be raised again.’ ” Then they remembered his words. When they came back from the tomb, they told all these things to the Eleven and to all the others - Luke 24:5-9

Then he opened their minds to understand the Scriptures, and said to them, “Thus it is written, that the Christ should suffer and on the third day rise from the dead, and that repentance for the forgiveness of sins should be proclaimed in his name to all nations, beginning from Jerusalem. You are witnesses of these things - Luke 24:45-48

According to Gospel of John

Jesus answered them, “Destroy this temple, and in three days I will raise it up.” The Jews then said, “It has taken forty-six years to build this temple, and will you raise it up in three days?” But he was speaking about the temple of his body. When therefore he was raised from the dead, his disciples remembered that he had said this, and they believed the Scripture and the word that Jesus had spoken - John 2:19-22

And Jesus found a young donkey and sat on it, just as it is written, “Fear not, daughter of Zion; behold, your king is coming, sitting on a donkey's colt!” His disciples did not understand these things at first, but when Jesus was glorified, then they remembered that these things had been written about him and had been done to him - John 12:14-16

According to Gospel of Mark

Afterward he appeared to the eleven themselves as they were reclining at table, and he rebuked them for their unbelief and hardness of heart, because they had not believed those who saw him after he had risen - Mark 16:14