2 Samuel 11:16

And it came to pass, when Joab observed the city
Where lay its greatest strength, and where it was best defended; or besieged it, as the Targum:

that he assigned Uriah unto a place where he knew that valiant men
[were];
who would not easily give way, and when they saw an opportunity would sally out, Joab cannot be excused from sin, unless he thought that Uriah had been guilty of death, and that David took this way of dispatching him for some political reason; however David was king, and to be obeyed.