Leviticus 25:14

And if thou sell ought unto thy neighbor, or buyest ought of thy neighbor's hand, ye shall not oppress one another:

"'If you sell anything to your neighbor, or buy from your neighbor, you shall not wrong one another.

And if thou sell aught unto thy neighbor, or buy of thy neighbor's hand, ye shall not wrong one another.

`And when thou sellest anything to thy fellow, or buyest from the hand of thy fellow, ye do not oppress one another;

If you make a sale to your neighbor or a purchase from him, you must not take advantage of each other.