What is the meaning of Matthew 26:55-56?

55 In that same hour said Jesus to the multitudes, Are ye come out as against a thief with swords and staves for to take me? I sat daily with you teaching in the temple, and ye laid no hold on me. 56 But all this was done, that the scriptures of the prophets might be fulfilled. Then all the disciples forsook him, and fled. (Matthew 26:55-56 KJV)

William Burkitt’s Commentary

We had an account of our Lord’s apprehension in the former verses; here, the sad effect of it upon his disciples: They all forsook him, and fled. Had this been done by the giddy multitude who followed him for the loaves, it had been no cause of wonder; but for those who had already forsaken all to follow him, who were faithful though fearful friends; what an addition to his sufferings must this be! no doubt, but the ingratitude of his friends made deeper wounds in his soul than the malice of enemies could make in his body. They that said all to Christ, verse 35, Though we should die with thee, yet we will not deny thee, do here all of them desert and forsake him; when it came to the push, not a man of them stands by him.

Learn thence, That the holiest of men know not their own hearts when great temptations and trials are before them, till they come to grapple with them, and to be engaged in them. We know not our own strength till temptation puts us to the proof.