John 11 51
He didn't say this on his own behalf, but as chief priest that year he was prophesying that Jesus would die for the nation.
Compare with other 3 random translations
ERV John 11:51Caiaphas did not think of this himself. As that year’s high priest, he was really prophesying that Jesus would die for the Jewish people.
GNV John 11:51This spake hee not of himselfe: but being hie Priest that same yere, he prophecied that Iesus should die for that nation:
NLT John 11:51He did not say this on his own; as high priest at that time he was led to prophesy that Jesus would die for the entire nation.