The religious leadership is looking for a way to kill Jesus, and Judas offers to provide the opportunity. Notice that “Satan entered Judas,” which is possible because Judas apparently didn’t really believe (John 6:64).
Everything is ready for Jesus to celebrate the Passover with His disciples. His additions will make a meal that already celebrates salvation even more meaningful. He promises that He will celebrate it with them again, but not until the Messianic banquet!
Revelation 19:9 “Then the angel said to me, ‘Write the following: Blessed are those who are invited to the banquet at the wedding celebration of the Lamb!’ He also said to me, ‘These are the true words of God.'”
Jesus not only lets them know about the coming betrayal, He warns Peter about his upcoming denial. But it’s not just Peter! The Net Bible brings out the plural: “Satan has demanded to have you all!” Jesus encourages Peter by letting Him know his denial isn’t permanent. It’s quite likely that Satan also demands to test us, but we shouldn’t worry. Paul reminds us that God walks with us through whatever trials we face:
1 Corinthians 10:13 “No trial has overtaken you that is not faced by others. And God is faithful: He will not let you be tried beyond what you are able to bear, but with the trial will also provide a way out so that you may be able to endure it.”
We also have a reminder here that humility is something that helps us keep faithful. We shouldn’t think that we are the best or the most important. Jesus served, we should serve. If we have that mindset, we are much more likely to withstand any trials or temptations that come our way, because we will understand our need for help, guidance, and strength.
Why do you think that Jesus now instructs them to take supplies with them on their journeys? I think that the best understanding is that their ministry is about to get harder, shown by the very fact that Jesus isn’t going to be with them anymore: “Scripture must be fulfilled in me.” They need to be prepared for that, even to the point of defending themselves against robbers on the road, not starting an insurrection!