A.T. Robertson 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 (κα αυτος). Emphatic, and he himself.

A large upper room (αναγαιον μεγα). Anything above ground (γη), and particularly upstairs as here. Here and in Lu 22:12. Example in Xenophon. Jesus wishes to observe this last feast with his disciples alone, not with others as was often done. Evidently this friend of Jesus was a man who would understand.

Furnished (εστρωμενον). Perfect passive participle of στρωννυμ, state of readiness. "Strewed with carpets, and with couches properly spread" (Vincent).