Matthew 17:22 - 23

22 Now while they were staying in Galilee, Jesus said to them, “The Son of Man is about to be betrayed into the hands of men,

23 and they will kill Him, and the third day He will be raised up.” And they were exceedingly sorrowful.

Before leaving Galilee, Jesus informs the disciples of Him being given to the wicked men.

He then tells them He will be killed. They are so focused on His death they ignore the part about Him being raised from the dead on the third day. His death makes them very sad.