Albert Barnes 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)

A large upper room. The word used here denotes the upper room devoted to purposes of prayer, repose, and often of eating. See Barnes Matthew 9:2.

Furnished and prepared. Literally, spread and ready. Spread with a carpet, or with couches, such as were used in eating. See Barnes Matthew 23:6.