وَبَيَّنَ فِيهَا أَمْرَهُ وَنَهْيَهُ
In those books He made His commands and prohibitions clear.
A command directs people to a required or desired action, whereas a prohibition restrains them from a forbidden action. Both concern conduct and accountability, although not every command or prohibition necessarily carries an identical juristic degree.
For example, an instruction to perform worship and a prohibition of injustice are different forms of address: one directs conduct and the other marks out prohibited behavior. Revealed guidance therefore has a practical dimension.