Luke 19:35

‘And they brought him to Jesus, and they threw their garments on the colt, and set Jesus on it.'

The disciples then brought the colt to Jesus, threw their garments on it, and set Jesus on it. This was a further action indicating the royalty of the rider. We can compare this with 1 Kings 1:33 where a similar action precedes the crown prince's coronation. The garments would be in order to enable a comfortable ride, but it may well be that one of the garments was put over the colt's eyes so as to keep it from panicking while the process of mounting took place. A young, previously unridden, colt would be frisky.

Neither Luke nor Mark does not mention that it was an ass on which Jesus rode, but Matthew 21:2 stresses it. We must not underestimate this. The ass was looked on by the Jews as a noble beast. When kings rode in peace they regularly rode on an ass. Thus the prophecy, and Jesus' action in riding on an ass, revealed Him as a King, but it also revealed that He came, not as a warrior on His war horse, but as the lowly Prince of Peace (Isaiah 9:6). He had not come as the kind of Messiah that most Jews were expecting.