What does Matthew 26:19 mean?

Jesus has given the disciples directions for finding the place where they will observe the Last Supper. It is not clear whether He had made prior arrangements. He may have been relying on the Spirit to prepare the owner of the house to be ready for Jesus and the disciples to meet there. It may be that there was a level of secrecy involved since Jesus understood the Jewish religious leaders wanted to arrest and kill Him. That would happen later in the evening (Matthew 26:47), but not before He had completed His time with the disciples.

Some Bible scholars speculate that the house with the upper room was owned by the father of John Mark, though there is no hard evidence for this. In any case, the room was provided, and the disciples prepared for the Passover meal in keeping with the Jewish Scriptures. They would eat it together after sundown, as the first day of the Passover week officially began.