Capping Interest
The Code of Hammurabi sets ceilings on the interest a loan may carry: about thirty-three per cent a year on grain, twenty on silver. A lender who took more than the cap forfeited both the interest and the principal. Trade had barely begun before the rules of trade arrived. The stele itself is in the Louvre (inventory Sb 8), found in three broken pieces at Susa in Iran over the winter of 1901–02. It turned up at Susa rather than Babylon because an Elamite king carried it off as spoil after Hammurabi's death. And the finest detail may be the carving at the top: the sun god Shamash conferring authority on the king — the same god as the model next door, Lending from the Temple. The side that lent at interest and the side that capped it both stood in the name of the same god. The king also held one more card, the mīsharum or «justice» edict, cancelling debts on his accession and at other moments; Hammurabi issued four. Only the debts of ordinary people were wiped, however — dealings between merchants were exempt. The jubilee was designed so as not to stop trade.
The myth, corrected
The Code of Hammurabi was law, applied as written in court
There is almost no evidence that the stele carrying these interest caps was ever applied to the letter in an actual case. The current reading is that it is a monument proclaiming the king's justice, and that calling it a «law code» at all invites misunderstanding. Being cut into stone and being obeyed are two different things.