The Impostor

A certain man fell ill, and, being in a very bad way, he made a vow
that he would sacrifice a hundred oxen to the gods if they would grant
him a return to health. Wishing to see how he would keep his vow, they
caused him to recover in a short time. Now, he hadn't an ox in the
world, so he made a hundred little oxen out of tallow and offered
them up on an altar, at the same time saying, "Ye gods, I call you to
witness that I have discharged my vow." The gods determined to be even
with him, so they sent him a dream, in which he was bidden to go to
the sea-shore and fetch a hundred crowns which he was to find there.
Hastening in great excitement to the shore, he fell in with a band of
robbers, who seized him and carried him off to sell as a slave: and
when they sold him a hundred crowns was the sum he fetched.

Do not promise more than you can perform.