The laws mentioned above apply to fields and homes in un-walled cities. Homes in walled cities, on the other hand, may only be redeemed up to one year after the sale; otherwise they become the permanent property of the buyer. Another exception to these rules is the property allotted to the Levites, which are always redeemable. We are commanded to assist our brethren by coming to their aid before they become financially ruined and dependent on the help of others. We are also forbidden from charging interest on a loan to a fellow Jew.