What does Luke 24:43 mean?

The large group of disciples have heard from several women and three men that Jesus has risen from the dead. But many of them saw Jesus die (Luke 23:49). They witnessed the brutality He suffered. They saw or heard about Jesus raising Lazarus from the dead (John 11), but how can Jesus raise Himself? When Jesus comes into the room where they are hiding (John 20:19), they still doubt. Jesus graciously gives them the evidence they need.

John is the only other gospel writer who records this night; he doesn't mention Jesus eating fish. It was a tradition in Judaism that spirits can't eat. Although Jesus' glorified body doesn't need sustenance, His disciples do need reassurance. So, after He shows the wounds on His hands and feet and invites the people in the room to touch Him, He asks for something to eat (Luke 24:39–42).

Each gospel writer has a particular message to his readers; even the three Synoptic Gospels—Matthew, Mark, and Luke—do not record all the same events between Jesus' resurrection and ascension. On this night, John includes words from Jesus which Luke does not mention.

Jesus tells the disciples, "As the Father has sent me, even so I am sending you" (John 20:21). He then breathes on them and gives them the Holy Spirit. This is confusing since the Holy Spirit doesn't come to indwell Jesus' followers until about ten days after His ascension (Acts 2:1–4). On this night, the disciples do not receive the permanent indwelling of the Spirit. They seem to receive the filling of the Spirit in the tradition of John the Baptist and the prophets of the Old Testament. This filling is what they need for the coming weeks. It's not known if the doubters of Matthew 28:17 receive the Holy Spirit here.