Luke 22:10
And he said unto them, Behold, when ye are entered into the city, there shall a man meet you, bearing a pitcher of water; follow him into the house where he entereth in. And he said unto them, Behold, when ye are entered into the city, there shall a man meet you, bearing a pitcher of water; follow him into the house where he entereth in.
Peter and John, who were to be closely associated in labor, were sent to prepare the Passover supper. The place to be prepared was the upper chamber of a dwelling at Jerusalem, where Jesus would eat the Passover supper with His disciples. The sign for finding it was that when they entered the city a man bearing a pitcher of water would meet them, and they were to follow him into the house where he entered.
The secrecy of the sign guarded against premature movements by traitors coming to the supper to join the action designed by Judas. Two Galileans could so address a stranger because those living in Jerusalem customarily accommodated strangers desiring to celebrate the Passover. The disciples met the man, followed him, delivered the message, and found ready assent. The directions came true exactly, and the disciples found things just as Jesus had said.
This Passover gathering came before the sacramental service Christ established to replace the Passover as a lasting memorial of His death. The supper came before Jesus went with His disciples to the garden of Gethsemane, where He often went to pray.