God sometimes allowed what was less than ideal because people's hard hearts made the ideal unattainable (for example, Ex 13:17; 1 Sam 12:12-13). To be able to exercise some restraint over human injustice, Moses' civil laws regulated some institutions rather than seeking to abolish them altogether: divorce, polygyny, the avengers of blood, and slavery (Keener 1992b:192-96). Jewish lawyers themselves recognized that God had allowed some behavior as a concession to human weakness (Daube 1959).

Nevertheless, Jesus' opponents here assume that whatever the law addresses it permits (Mt 19:7). Jesus responds that Moses permitted this merely as a concession to Israel's hard hearts, implying that his questioners who exploit this concession also have hard hearts. Thus in Matthew (in contrast to Mark) the Pharisees even exploit Moses' concession as a command (Gundry 1982:380). American slaveholders were similarly sure that the practice of slavery in biblical times proved the Bible's approval of slavery (Sawyer 1858), the same way Muslim slaveholders applied the Qur'an (Gordon 1989:xi; B. Lewis 1990:78). Some husbands today twist biblical teachings to justify abusing their wives (see, for example, Alsdurf and Alsdurf 1989). And some churches use Jesus' words in this very passage-words that may have been meant to protect an innocent Jewish wife from being wrongfully divorced by her husband (Kysar and Kysar 1978:43; France 1985:280; M. Davies 1993:54)-to batter innocent parties in divorces. Human nature has changed very little in two millennia.