Placed there to defend it, because that part of the city was supposed either the weakest, or the place designed for the assault. Joab having formerly committed a base murder upon Abner, was ready to execute this wicked command of the king; that so he being involved in the same guilt with him, might the more willingly receive him into favour.
Related Commentaries of 2 Samuel 11:16
2 Samuel 11:16
16 And it came to pass, when Joab observed the city, that he assigned Uriah unto a place where he knew that valiant men were.