A.T. Robertson Commentary John 13:11

"For he knew him that should betray him; therefore said he, Ye are not all clean." — John 13:11 (ASV)

For he knew him that should betray him (ηιδε γαρ τον παραδιδοντα αυτον). Past perfect ηιδε used as imperfect. Jesus had known for a year at least (6:64,70) and yet he treated Judas with his usual courtesy. The articular present participle of παραδιδωμ, "the betraying one," for Judas was already engaged in the process. Did Judas wince at this thrust from Jesus?