Origin English saying

Can anybody tell me more about the origin of an old English saying "A sign is no use, unless a man on a galloping horse can read it"?
Like when its dated (What century) etc.

A blind man on a galloping horse is frequently put forward as someone with poor perception. If he can notice something, anyone can. Its use is current, but I don't know its origin. As you suggest, it's not a modern image.