Mark 9:9-10, 31-32

Now as they came down from the mountain, He commanded them that they should tell no one the things they had seen, till the Son of Man had risen from the dead. So they kept this word to themselves, questioning what the rising from the dead meant.

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.