What does Luke 22:12 mean?

Jerusalem is filled with tens or hundreds of thousands of travelers, not to mention residents. Ideally, Passover is to be celebrated in the temple court. But when Jerusalem is filled with too many people, groups meet throughout the city. Jesus has told Peter and John to prepare a meal for thirteen people: Jesus and the twelve disciples. They can get the food easily enough, but they need a room (Luke 22:7–9).

Jesus gives them seemingly random instructions: go into the city gate and follow a man carrying a jar of water. This man will lead them to a house. Tell the master of the house that "The Teacher" is coming and wants to know where the guest room is (Luke 22:10–11). Not only will they find a room, but it will be fully furnished with a table and enough reclining couches for all of them.

Considering all Jesus wants to say to His disciples (John 13–17), the upper room is ideal. It is here that Jesus will wash the disciples' feet in a living example of servant-leadership. He will tell the disciples that one of them will betray Him but all of them will abandon Him. Most heart-breaking, He will reveal that He is leaving—returning to the Father—and they cannot follow.

But He also promises them the Holy Spirit: God in them. The Holy Spirit will guide them as they spread the news about Jesus' resurrection and build the church. In fact, within fifty days of this meal, Jesus will have died, resurrected, and ascended into heaven. The Spirit will have indwelt His followers. And Peter will stand before a crowd of thousands who have come to Jerusalem for Pentecost, sharing the good news (Acts 2).