John Chrysostom
The disciples who had remained when the Lord was apprehended, fled when He spoke these things to the multitudes, Then all the disciples forsook him and fled; for they then understood that He could not escape but rather gave Himself up voluntarily.
They did not lay hands on Him in the temple because they feared the multitude, therefore also the Lord went forth that He might give them place and opportunity to take Him. This then teaches them, that if He had not suffered them of His own free choice, they would never have had strength to take Him. Then the Evangelist assigns the reason why the Lord was willing to be taken, adding, All this was done that the Scriptures of the Prophets might be fulfilled.
Great was the zeal of Peter, who fled not when He saw the others fly, but remained, and entered in. For though John also went in, yet he was known to the Chief Priest. He followed afar off, because he was about to deny his Lord.