What does Matthew 26:15 mean?

Under the influence of Satan (John 13:2, 27), one of Jesus' chosen twelve disciples, Judas Iscariot, has made a traitorous decision. He will betray the Lord to the Jewish religious leaders who want to arrest and kill him (John 13:3–4). Matthew positions this decision following Jesus' correction of the disciples over expensive ointment. They said the woman who anointed Jesus should have sold the oil and given the money to the poor. Jesus insisted she was preparing His body for burial (Matthew 26:1–14).

John 12:6 reveals that Judas was already stealing from the group moneybag at this point. He may have been growing in disillusionment with Jesus' approach to Rome, the Pharisees, and Israel. His decision now to betray Jesus also comes with an apparent financial motive. He asks the chief priests what they will give him to deliver Jesus over to them. They pay Judas 30 pieces of silver.

This was not a large amount of money. It is the amount in the law that was to be paid by the owner of an ox that accidentally gored a slave to death (Exodus 21:32). Zechariah only sarcastically referred to this as a "lordly price" (Zechariah 11:13). It is a shockingly low amount for the betrayal of the Son of God, of course, and it reveals how little value Israel's religious leaders placed on Jesus. It also suggests that Judas' motivations might have been personal, in that he perhaps came to resent Jesus and His mission.