# The Son of Man must suffer ... and he will be killed

Jesus is referring to himself. Alternate translation: "I, the Son of Man must suffer ... and I will be killed" 

# and be rejected by the elders and chief priests and scribes

"and the elders, chief priests, and scribes will reject him"

# he will be killed

"they will kill him" 

# on the third day

"three days after he dies" or "on the third day after his death"

# be raised

"God will make him alive again" or "he will live again"