Once upon a time, the tale goes, a man was sentenced to death by the king.

"Wait!" he cried. "If you delay my sentence by six months, I'll teach your horse to talk."

The king agreed.

Later that day the man's wife asked him, "Why would you make such an offer? You can't possibly teach a horse how to talk."

"Well," he answered, "I figure a lot can happen in six months. There could be a revolution and a new king. Or the king could get sick and die. Or the king could change his mind. Or the horse could die. Or I could die. Or maybe the horse will talk."

Apparently from The Truth Machine by James L. Haperlin