Albert Barnes Commentary Mark 10:32-34

"And they were on the way, going up to Jerusalem; and Jesus was going before them: and they were amazed; and they that followed were afraid. And he took again the twelve, and began to tell them the things that were to happen unto him, [saying], Behold, we go up to Jerusalem; and the Son of man shall be delivered unto the chief priests and the scribes; and they shall condemn him to death, and shall deliver him unto the Gentiles: and they shall mock him, and shall spit upon him, and shall scourge him, and shall kill him; and after three days he shall rise again." — Mark 10:32-34 (ASV)

Jesus went before them. In the manner of an intrepid, fearless leader and guide, exposing himself to danger and death rather than his followers.

And they were amazed, etc. They were afraid that evil would befall him in the city; that the scribes and Pharisees, who had so often sought to kill him, would then do it. Their fear and amazement were increased when he told them what would befall him there. They were amazed that, when he knew so well what would happen, he should still persevere in going up to the city.