Jesus told his disciples to go into the city and follow a man carrying a pitcher. That person would enter a home, and they should tell the master of the house that the Teacher needed his upper room to use for the Passover.
This was another miraculous event because everything happened as Jesus said it would.
It was unusual for a man to be carrying a pitcher. And I suppose it was very unusual to find a spare room anywhere in the city during Passover week: and yet there it was. The owner turned it over to the Disciples and they began preparations for the feast.