The disciples answered as Jesus had instructed them, and the people gave them permission.
We have here the story of the public entry Christ made into Jerusalem, four or five days before his death. And he came into town thus remarkably, 1. To show that he was not afraid of the power and malice of his enemies in Jerusalem.
Commenting on Mark 11:1-11
And they said unto them,.... The very express words, even as Jesus had commanded: not that these were the words they said, but "the Lord hath need of him": upon which they said no more, were satisfied and contented, that they should untie the colt, and take it with them: and they let them go; and the colt with them, very freely; See Gill on Mat 21:6.
And they let them go - Having a full assurance that the beast should be safely and speedily restored.