Verse 15
Mark 14:15
Large upper room -- The house where they met for the Lord’s last supper with them, was perhaps the house belonging to Mary, the sister of Barnabas and mother of Mark, where they assembled in Acts 12:12; see Colossians 4:10; Acts 12:25. It was a large house and the owner had servants. Such large complexes kept an upper room for guests. Especially in Jerusalem they kept them for visitors who came to the feasts. This household appears to have been disciples or at least sympathizers of the Rabbi from Galilee.
One clue that makes us think this, is Mark’s statement in Mark 14:51 where it is believed that Mark is referring to himself. If Mark was the one following Jesus and the apostles to the garden, it would probably have been that he followed them from his home when they left in the night. Probably already in bed he only grabbed a linen cloth (sheet) to wrap around his naked body and followed them.
Most likely it is also the same house where the disciples met (hid) after the Lord’s crucifixion John 20:19; John 20:26;
It could also be the same house mentioned in Acts 1:13, Acts 2:2.