Three Hundred Æsop's Fables/The Lion and the Eagle
THE LION AND THE EAGLE.
An Eagle stayed his flight, and entreated a Lion to make an alliance with him to their mutual advantage. The Lion replied, "I have no objection, but you must excuse me for requiring you to find surety for your good faith; for how can I trust any one as a friend, who is able to fly away from his bargain whenever he pleases?"
Try before you trust.