New Defender's Study Bible Notes
21:2 a colt with her. The parallel accounts in Mark 11:2 and Luke 19:30 only mention one donkey, but that does not mean they deny that two were involved. Also, Matthew is the only one who mentions that this incident was in fulfillment of the prophecy of Zechariah 9:9, but the others must have known this reference.
21:4 spoken by the prophet. See Zechariah 9:9. Here for the first time publicly, Christ presented Himself to the Jews as their promised Messiah and King.