John Gill Commentary Mark 14:15

"And he will himself show you a large upper room furnished [and] ready: and there make ready for us." — Mark 14:15 (ASV)

And he will show you a large upper room

A room in the highest part of the house, large enough for such a company, for thirteen persons, which was the number of Christ and his disciples:

furnished and prepared ;

with a table, and a sufficient number of couches to sit, or lie upon, and with all proper vessels necessary on such an occasion:

there make ready for us ;

the passover.