Then entered Satan into Judas - It is not necessary to suppose that Satan entered personally into the body of Judas, but only that he brought him under his influence; he filled his mind with an evil passion, and led him on to betray his Master. The particular passion of which Satan made use was "avarice" - probably the besetting sin of Judas. To show its exceeding evil and baseness, it is only necessary to say that when it produced its "appropriate" effect in this case, it led to the betraying and crucifixion of the Son of God. We may learn, also, that when Satan "tempts" people, he commonly does it by exciting and raising to the highest pitch their native passions. He does not make them act contrary to their nature, but leads them on to "act out" their proper disposition.
Satan - This word properly means an adversary or an accuser. It is the name which in the Scriptures is commonly given to the prince or leader of evil spirits, and is given to him because he is the "accuser or calumniator" of the righteous (see Revelation 12:10; compare Job 1:6-9), as well as because he is the "adversary" of God.
Being of the number of the twelve - One of the twelve apostles. This greatly aggravated his crime. He should have been bound by most tender ties to Jesus. He was one of his family - long with him, and, treated by him with every mark of kindness and confidence; and nothing could more enhance his guilt than thus to make use of this confidence for the commission of one of the basest crimes.

Then entered Satan into Judas - The devil filled the heart of Judas with avarice; and that infamous passion led him to commit the crime here specified. This at once accounts for the whole of this most unprincipled and unnatural transaction. None but a devil, or he who is possessed by one, could have been guilty of it: - let the living lay this to heart. A minister of the Gospel, who is a lover of money, is constantly betraying the interests of Christ. He cannot serve two masters; and while his heart is possessed with the love of self, the love of God and zeal for perishing souls cannot dwell in him. What Satan could not do by the envy and malice of the high priests and Pharisees, he effects by Judas, a false and fallen minister of the Gospel of God. None are so dangerous to the interests of Christianity as persons of this stamp.

(2) Then entered Satan into Judas surnamed Iscariot, being of the number of the twelve.
(2) God by his wonderful providence causes him to be the minister of our salvation who was the author of our destruction.

Then entered Satan into Judas,.... At the same time that the sanhedrim were sitting, and consulting about the death of Christ, Satan, or the adversary, as the word signifies, the devil, who is the enemy of the Messiah, the woman's seed, entered into Judas; not corporeally, as he did into those that were possessed by him; but he entered "into his heart", as the Ethiopic version renders it; he put it into his heart to betray him, as it is said in John 13:2 he stirred up, and worked upon the corruptions of his heart; suggested evil things to his mind, and baited his temptations agreeable to his malice and covetousness: and this man was
surnamed Iscariot; to distinguish him from another apostle of the same name; concerning this his surname; see Gill on Matthew 10:4, See Gill on John 13:2.
Being of the number of the twelve; apostles, or disciples of Jesus, as the Persic version reads, and which is an aggravation of his sin: now this being two days before the passover, shows, that the sop which Judas took, after which the devil entered into him, John 13:27 could not be the passover sop, but was the sop he ate at the supper in Bethany, in the house of Simon the leper, so long before it.

Then entered Satan, &c.--but not yet in the full sense. The awful stages of it were these: (1) Covetousness being his master--passion, the Lord let it reveal itself and gather strength by entrusting him with "the bag" (John 12:6), as treasurer to Himself and the Twelve. (2) In the discharge of that most sacred trust he became "a thief," appropriating its contents from time to time to his own use. Satan, seeing this door into his heart standing wide open, determines to enter by it, but cautiously (2-Corinthians 2:11); first merely "putting it into his heart to betray Him" (John 13:2), suggesting the thought to him that by this means he might enrich himself. (3) This thought was probably converted into a settled purpose by what took place in Simon's house at Bethany. (See Matthew 26:6, and see on John 12:4-8.) (4) Starting back, perhaps, or mercifully held back, for some time, the determination to carry it into immediate effect was not consummated till, sitting at the paschal supper, "Satan entered into him" (see on John 13:27), and conscience, effectually stifled, only rose again to be his tormentor. What lessons in all this for every one (Ephesians 4:27; James 4:7; 1-Peter 5:8-9)!

And Satan entered into Judas. He gave himself up to do the work of Satan. See notes on Matthew 26:14-16.

Then entered Satan - Who is never wanting to assist those whose heart is bent upon mischief.