en_tn/mat/26/23.md

Jesus continues to teach his disciples as he eats the Passover meal with them.

that man by whom the Son of Man is betrayed

"the man who betrays the Son of Man"

You have said it yourself

"As you have said, you are the one" or "You have just admitted it" (See: rc://en/ta/man/translate/figs-idiom)