We come to the point where we jump over a lot of Luke because his witness is duplicated elsewhere. Indeed, the only thing left unique to Luke’s Gospel is right before the Ascension.
During His last forty days on the earth in His resurrected body, Jesus placed a lot of emphasis on teaching the Apostles to restore the mystical understanding of things inherent in Hebrew culture and language. The Pharisees had taught them to take literally things meant symbolically, and tended to take as metaphor things that were mean literally. So there were several scenes where He appeared to them and invited their examination to prove He was risen to a genuine physical form, but a resurrected body that did not suffer spatial and temporal restrictions.
During those three years up to this point, they spent more time in Old Testament Scripture than they likely had ever seen during their entire lifetime before. Luke recounts the experience on the Road to Emmaus and notes Jesus reviewed with two of them a large amount of Old Testament passages. In so doing, He restored those passages to their proper ancient context, wiping away the already vast body of Pharisaical oral lore that perverted the meaning of Scripture. He showed them how everything that had happened was predicted in the Word.
Luke recounts one final meeting during those forty days that is mentioned elsewhere, but adds a bit of dialog no one else shares. A key element in Jesus’ teaching had always been that His ministry was to fulfill the Messianic Promises in the Old Testament. There was a sense in which He also brought to fruition everything the Covenant of Moses was supposed to accomplish, to pick up the broken ruins of and rebuild, finishing all the things Israel had failed to do.
A primary element in that mission of the Covenant was to make it possible for people to reach a point of enlightenment, a connection to Eternity that made it possible to understand everything instinctively. In the Old Testament, with sufficient commitment, and sufficient length and depth of exposure to the written record, it was possible to reach the place where the fire of revelation burned within the soul. This was the ostensible goal of the Covenant and the Scriptures. All the rituals and sacrifices were designed to help with the process.
But now Jesus had made that final sacrifice that ended the need for the rituals. The door to Heaven was open. So in that moment Jesus gave them a foretaste of the what the coming of the Holy Spirit would do very soon in their lives. He granted them a connection between their hearts and minds as a direct miraculous gift, so that there was no longer any need to strive for that enlightenment. Suddenly, their hearts were awakened and their minds were able to grasp the symbolism of it all. All of the things He had taught them for three years now suddenly awakened in their souls and it all made sense.
Now they understood whey He had to die. This purchased for them everything they otherwise would have spent the rest of their lives pursuing. They now had that burning sense of mission to bear this truth to the whole world, making them quite willing to follow Him to the Cross. All the rituals were aimed at keeping alive the sense of conviction over the Fall, but this final sacrifice of Christ also brought to the penitents a sense of acceptance, of peace with God. It all came as a free gift up front, rather than as the result of a lifetime of devotion.
Now they were free to live that devotion from the starting point. And it was their mission to carry that incredible good news to the whole world. However, they were told to wait just a little longer for that final touch from God. The day of divine vestment would come soon, so wait in Jerusalem until it arrives.