Matthew 20:19

“And will deliver him to the Gentiles to mock, and to scourge, and to crucify, and the third day he will be raised up.”

The fact that He must die means that Jesus is aware from the beginning that it will be at the hands of the Romans, for they alone had the power to carry out the death sentence. But here it is spelled out for the first time, as is the fact that His death will be by crucifixion. This would come as no surprise to One who had constantly spoken of taking up the cross. Indeed the whole process simply indicates the normal expectation for a condemned Jewish criminal, mockery, scourging and crucifixion. Jesus would have heard of it being carried out on the followers of Judas the Galilean when He was a lad, and He may well have witnessed such incidents Himself. The only unusual feature, given that He is to be executed, is that He will be raised on the third day. For this see on Matthew 16:21. The resurrection of the Suffering Servant is assumed in Isaiah 53:10, and implied in Daniel 7:13.