Origen

The opportunity which Judas sought is further explained by Luke, how he might betray him in the absence of the multitude; (Luke 22:6.) when the populace was not with Him, but He was withdrawn with His disciples. And this he did, delivering Him up after supper, when He was withdrawn to the garden of Gethsemane. And from that time forward, such has been the season sought for by those that would betray the word of God in time of persecution when the multitude of believers is not around the word of truth.