And when Judas had taken the morsel, Satan entered into him. Then Jesus said to Judas, “What you are about to do, do quickly.”
And after the sop, Satan entered into him,.... After he had taken and eaten the sop, or crust of bread, by which he was pointed out to be the betrayer, "Satan entered into him"; possessed his body, and filled his mind, and stirred him up more eagerly to pursue with rigour his wicked design.
THE TRAITOR INDICATED--HE LEAVES THE SUPPER ROOM. (Joh 13:21-30) When Jesus had thus said, he was troubled in spirit, and testified, and said, Verily, verily, I say unto you, One of you shall betray me--The announcement of Joh 13:18 seems not to have been plain enough to be quite apprehended, save by the traitor himself. He will therefore speak it out in terms not to be misunderstood.
Commenting on John 13:21-30
after the sop Satan entered into him--Very solemn are these brief hints of the successive steps by which Judas reached the climax of his guilt. "The devil had already put it into his heart to betray his Lord." Yet who can tell what struggles he went through ere he brought himself to carry that suggestion into effect? Even after this, however, his compunctions were not at an end.