Once again, Jesus showed supernatural knowledge (knowledge beyond normal human ability; see 1:47–49; 4:16–19). He knew what was in people’s hearts (their innermost selves) and what would happen in the future.
Jesus knew that Judas would betray him. Judas later betrayed Jesus to the authorities (12:4; 13:2; Matthew 26:14–16).
Iscariot means “man from Kerioth.” Kerioth was the home village of Judas’s family.