An ancient king once asked his three daughters how much they loved him. One daughter said she loved him more than all the gold in the world. One said she loved him more than all the silver in the world. The youngest daughter said she loved him more than salt. The king was not pleased with this answer. But the cook overheard the conversation, so the next day he prepared a good meal for the king, but left out the salt. The food was so insipid that the king couldn't eat it. Then he understood what his daughter meant. He understood the value of salt.

In the ancient world salt was a valuable and scarce commodity. It was used as currency in some countries even into modern times. During an invasion of Ethiopia, in the late 19th century, Italian soldiers found blocks of salt stored in bank vaults along with other familiar forms of currency. Jesus was paying his disciples a compliment when he called them salt.