Cast thy law behind their backs, i.e. neglected and despised thy laws, would not regard nor observe them; whereas they should have had them continually before their eyes, to direct and govern them. Compare Psalms 50:17 Ezekiel 23:35.
Related Commentaries of Nehemiah 9:26
Nehemiah 9:26
26 Nevertheless they were disobedient, and rebelled against thee, and cast thy law behind their backs, and slew thy prophets which testified against them to turn them to thee, and they wrought great provocations.