What does Matthew 26:56 mean?

Jesus has told His own disciples not to fight to defend Him from being arrested (Matthew 26:51–54), and now He has mocked those who have come for Him. They brought a miniature army, with clubs and swords, as if they would need those to capture some violent bandit. Christ is making it clear that He is going willingly with those who have come for Him (Philippians 2:8; Matthew 26:42).

At least one reason for these declarations is to prevent anyone else from getting hurt. John said that Jesus clearly identified Himself and told those who had come to arrest Him to let His disciples go (John 18:8). Along those same lines, He instantly healed the man Peter had wounded and told Peter and the others not to fight (Luke 22:51).

Finally, Jesus emphasizes to everyone present that His arrest and the events to follow will fulfill the Scriptures of the prophets. Nothing is happening which is not supposed to happen. It's the opposite: this is the moment God has been engineering all along. Jesus will not stop it, because it's why He has come (John 18:36–37).

At those words all the disciples scatter into the darkness. Matthew writes that they "left him," in the sense that they all abandoned Jesus. This is what Jesus said they would do just a few hours earlier (Matthew 26:31). This is a natural reaction to being faced by an arresting mob. However, it's clear Jesus wanted the disciples to get away for their own safety. They need to be preserved to start, in the coming weeks and months, the work for which He had trained them (John 16:12–15).

For now, the disciples will feel the danger of being associated with Jesus. They will experience the confusion and sadness resulting from His arrest and conviction (John 20:19).