Mark 14:10,11

Ver 10. And Judas Iscariot, one of the twelve, went unto the Chief Priests, to betray Him unto them. 11. And when they heard it, they were glad, and promised to give him money. And he sought how he might conveniently betray Him.

Bede: The unhappy Judas wishes to compensate with the price of his Master for the loss which he thought he had made by the pouring out of the ointment.

Where it is said: "And Judas Iscariot, one of the twelve, went unto the Chief Priests to betray Him unto them."

Chrysostom, de Prod. Jud., Homily 1: Why dost thou tell me of his country? would that I could also have been ignorant of his existence. But there was another disciple called Judas the zealot, the brother of James, and lest by calling him by this name there should arise a confusion between the two, he separates the one from the other. But he says not Judas the traitor, that he may teach us to be guiltless of detraction, and to avoid accusing others. In that however he says, "one of the twelve", he enhanced the detestable guilt of the traitor; for there were seventy other disciples, these however were not so intimate with Him, nor admitted to such familiar intercourse. But these twelve were approved by Him, these were the regal band, out of which the wicked traitor came forth.

Pseudo-Jerome: But he was one of the twelve in number, not in merit, one in body, not in soul. But he went to the Chief Priests after he went out and Satan entered into him. Every living thing unites with what is like itself.

Bede: But by the words, "he went out", it is shown that he was not invited by the Chief Priests, nor bound by any necessity, but entered upon this design from the spontaneous wickedness of his own mind.

Theophylact: It is said, to "betray him unto them", that is, to announce to them when He should be alone. But they feared to rush upon Him when He was teaching, for fear of the people.

Pseudo-Jerome: And he promises to betray Him, as his master the devil said before, "All this power I will give thee." [Luke 4:6]

It goes on, "And when they heard it they were glad, and promised to give him money." They promise him money, and they lose their life, which he also loses on receiving the money.

Chrysostom: Oh! the madness, yes, the avarice of the traitor, for his covetousness brought forth all the evil. For covetousness retains the souls which it has taken, and confines them in every way when it has bound them, and makes them forget all things, maddening their minds. Judas, taken captive by this madness of avarice, forgets the conversation, the table of Christ, his own discipleship, Christ's warnings and persuasion.

For there follows, "And he sought how he might conveniently betray Him."

Pseudo-Jerome: No opportunity for treachery can be found, such that it can escape vengeance here or there.

Bede: Many in this day shudder at the crime of Judas in selling his Master, his Lord and his God, for money, as monstrous and horrible wickedness. They however do not take heed, for when the sake of gain they trample on the rights of charity and truth, they are traitors to God, Who is Charity and Truth.