Leviticus 25:17

Ye shall not therefore oppress one another,.... By over or underrating estates:

but thou shalt fear thy God; and the fear of God being before their eyes, and on their hearts, would preserve both buyer and seller from doing an ill thing, when it was in the power of either, through the necessity of the one, or the ignorance of the other, see Ne 5:15:

for I [am] the Lord your God; omniscient, and knows all that is done in the most private and artful manner; and omnipotent and able to punish both, which of them either should oppress or defraud, see 1 Thessalonians 4:6.