“Betrayed” is actually the present participle “was betraying” when referring to the actions of Judas. The reason for this is that he was betraying Him at that very moment.

The rich had gardens on the Mount of Olives and one of them had given Jesus access to his garden to use as He pleased. He and His disciples probably stayed in that very garden all week, sleeping on the ground (Luke 21:37). Ryle notes that, “Excepting at the institution of the Lord’s Supper, we have no mention of our Lord ever being in any house in Jerusalem.”

Luke 21:37  Each day Jesus was teaching at the temple, and each evening he went out to spend the night on the hill called the Mount of Olives,