In the following excerpt, Emmet Fox points to the unicorn as a metaphor for this.
As long as we insist upon telling God His business, nothing very much can come of our prayers.
The ox, the mule, the donkey, will obediently pull your plow and your cart, and take them where you want to go; but you have to know where that is, and how to get there. The unicorn will not do chores. He will not pull a cart or turn a mill. He will not take orders.
The unicorn knows where he is going, and it is always somewhere that you could not choose because you never heard of it; and in your present consciousness you could not even dream that such a place could exist.
Nevertheless, there are such places, and the unicorn knows them, and is not interested in anything less. Someday it may happen, probably when you least expect it, that the unicorn will suddenly appear at your side, eyes flashing, nostrils quivering, pawing the ground with impatience. When that happens, do not try to put a bridle on him, or to look for some task for him to do. He will not do it, and there will not be time. No sooner, seemingly, has he appeared than off he will go again. So do not pause, but leap upon his back, for he is a flying steed, and he wings his way to the gates of the morning.
On that ride problems are not solved- they disappear.
Will the unicorn be willing to serve thee, or abide by thy crib? Canst thou bind the unicorn with his band in the furrow? or will he harrow the valleys after thee? (Job 39:9-10)
–From "Around the Year with Emmet Fox", September 8