Final answer:
David did something that was usually forbidden because he engaged in morally wrong acts, such as ordering killings and orchestrating the death of Uriah.
Step-by-step explanation:
David did something that was usually forbidden because he was a complex and controversial figure in biblical history. While he is praised as a great king and a man after God's own heart, he also committed several acts that were considered morally wrong. Some examples include ordering the killing of his enemies, orchestrating the death of Uriah to marry Bathsheba, and engaging in violent conquests.