And saith unto them, Go your way into the village over against you: and as soon as ye be entered into it, ye shall find a colt tied, whereon never man sat; loose him, and bring [him].
Note 4 at Mr 11:2: This is a very miraculous example of the gift of the Spirit called a word of knowledge, and this gift worked through Jesus quite often (see note 6 at Mr 2:8, note 2 at Lu 8:46, and note 3 at Joh 1:48). Jesus hadn't been in Jerusalem in quite a while, and there is no indication that He had made any previous arrangements with anyone in Jerusalem about this ass and her colt. This was nothing less than supernatural knowledge imparted to Jesus through the Holy Spirit.
Not only was it a miracle that Jesus knew about the ass and her colt and where they would be, but God had also worked some kind of miracle in the owner of these animals so that he would be willing to release them. It is possible that the Lord had also revealed to this man that Jesus would need his animals, or perhaps he was just a devoted follower of Jesus who gladly surrendered them when he knew Jesus was the one wanting them. Either way, it was just as much a miracle that the owner was willing to surrender them as it was that Jesus knew exactly where they would be.
Note 5 at Mr 11:2: Not only was there a miraculous manifestation of God's power in Jesus knowing where these animals were and that their owner would be willing to release them (see note 4 at Mr 11:2), but it was also a miracle that Jesus was able to ride upon a colt that had never been broken.
This is an example of how Jesus is Lord over creation (Col 1:16-17). He certainly has the same authority over mankind because we also are His creation, but one of the main differences between us and His animal creation is our free will. The Lord does not violate our free will except in judgment. These "dumb" animals submitted to Him, but those made in His own likeness and image didn't (Joh 1:11).