Even my close friend, whom I trusted,
he who shared my bread,
has lifted up his heel against me."
Psalm 41: 9
This verse is viewed in the New Testament as a prophecy of Christ's betrayal . Judas one of Jesus' 12 disciples had spent three years learning from Jesus, traveling and eating with him and handling the finances for the group. Eventually Judas, who knew Jesus extremely well, betrayed him (Matthew 26:14-16 and 20-25).
The apostle John writes in chapter 13:
When Jesus had finished washing their feet, he put on his clothes and returned to his place.
"Do you not understand what I have done for you?" he asked them. "You call me 'Teacher' and 'Lord,' and rightly so, for that is what I am. Now that I your Lord and Teacher, have washed your feet, you also should wash one another's feet. I have set you an example that you should do as I have done for you. I tell you the truth, no servant is greater than his master, nor is a messenger greater than the one who sent him. Now that you know these things, you will be blessed. "I am not referring to all of you; I know those I have chosen. But this is to fulfill the scripture: 'He who shares my bread has lifted up his heel against me.'
I am telling you now before it happens, so that when it does happen you will believe that I am He. I tell you truth, whoever accepts anyone I send accepts me; and whoever accepts me accepts the one who sent me.
"After he had said this, Jesus was troubled in spirit and testified, "I tell you the truth , one of you is going to betray me."
His disciples stared at one another, at a loss to know which of them he meant. One of them, the disciple who Jesus loved, was reclining next to him. Simon Peter motioned to this disciple and said, "Ask him which one he means."
Leaning back against Jesus, he asked him, "Lord who is it?"
Jesus answered, "It is the one to whom I will give this piece of bread when I have dipped it in the dish." Then, dipping the piece of bread, he gave it to Judas Iscariot, son of Simon. As soon as Judas took the bread, Satan entered into him.
"What you are about to do, do quickly," Jesus told him, but no one at the meal understood why Jesus said this to him. Since Judas was in charge of the money, some thought Jesus was telling him to buy what was needed for the Feast (of Passover), or to give something to the poor. As soon as Judas had taken the bread, he went out. And it was night. "
Bible notes -- Satan's part in the betrayal of Jesus does not remove any of the responsiblity from Judas. Disillusion because Jesus was taking about dying rather than setting up his kingdom. Judas may have been trying to force Jesus' hand and make him use his power to prove he was the Messiah. Or perhaps Judas, not understanding Jesus' mission, no longer believed Jesus was God's chosen one. Whatever Judas thought, Satan assumed that Jesus' death would end his mission and thwart God's plan. Like Judas, Satan did not know that Jesus' death was the most important part of God's plan all along.
NIV Life Application Study Bible notes: Psalm 41:9 & John 13:27, Zondervan Press