We are commanded not to leave a condition that may cause harm, to construct our homes in ways that will prevent people from being harmed, and to help a person whose life is in danger. These commandments regarding the preservation of life are so important in Judaism that they override all of the ritual observances that people think are the most important part of Judaism. We are commanded to help those in need, both in physical need and financial need. The Torah commands us to help a neighbor with his burden, and help load or unload his beast, to give money to the poor and needy, and not to turn them away empty handed. Jewish law forbids us from cheating another or taking advantage of another.
Jewish law regarding business ethics and practices is extensive.
Entire books have been written on the subject of Jewish laws against wronging another person in speech. We are commanded not to tell lies about a person, nor even uncomplimentary things that are true. We are commanded to speak the truth, to fulfill our promises, and not to deceive others. See Speech and Lashon Ha-Ra . Contrary to what many people think, most of these laws regarding treatment of others apply not only to our treatment of our fellow Jews, but also to our treatment of gentiles, and in many cases even to our treatment of animals .