Matthew 21: 1- 46 Hosanna!Hosanna! To the Highest!

King James Version
4 All this was done, that it might be fulfilled which was spoken by the prophet, saying,

5 Tell ye the daughter of Sion, Behold, thy King cometh unto thee, meek, and sitting upon an ass, and a colt the foal of an ass.

6 And the disciples went, and did as Jesus commanded them,

7 And brought the ass, and the colt, and put on them their clothes, and they set him thereon.

It was a ancient practice when a King entered a kingdom on a donkey He was coming in peace, but when a King entered on a horse He was coming for war.