“Simply let your ‘Yes’ be ‘Yes,’ and your ‘No’ be ‘No’.” The religious leaders in Jesus’ day had an elaborate system in which some oaths were binding and others were not. Jesus insisted that His disciples be people of the Word and people who keep their word. “An eye for an eye and a tooth for a tooth” was not intended to be a harsh demand for justice but rather a limit to the vengeance an offended person could take.
