What does John 12:12-16 mean?

12 On the next day much people that were come to the feast, when they heard that Jesus was coming to Jerusalem, 13 Took branches of palm trees, and went forth to meet him, and cried, Hosanna: Blessed is the King of Israel that cometh in the name of the Lord. 14 And Jesus, when he had found a young ass, sat thereon; as it is written, 15 Fear not, daughter of Sion: behold, thy King cometh, sitting on an ass’s colt. 16 These things understood not his disciples at the first: but when Jesus was glorified, then remembered they that these things were written of him, and that they had done these things unto him. (John 12:12-16 KJV)

William Burkitt’s Commentary

Here, we have recorded the carriage of the multitude towards our Saviour, when he came near the city of Jerusalem: they take palms in their hands, and go forth to meet him, and cast their garments on the ground before him to ride upon: yea, they do not only disrobe their backs, but expend their breath in joyful acclamations, and loud hosannas, wishing all manner of prosperity to their meek but mighty King.

In this prince-like, yet poor and dispicable pomp, doth our Saviour enter the famous city of Jerusalem.

Lord! how far wast thou from affecting worldly greatness and grandeur? Thou despisest that glory which our hearts fondly admire: yet because Christ was a King, he would be proclaimed such, and have his kingdom confessed, and applauded, and blessed: yet, that it might appear that his kingdom was not of this world, he abandons all worldly magnificence.