What does 2 Samuel 11:25 mean?

David told the messenger, 'Tell Joab, "Don’t let this upset you. The sword takes one person as easily as another. Keep up the attack on the city and destroy it." Encourage him for me.' 2 Samuel 11:25 - Modern Text Bible

(David acts unconcerned about the losses, especially Uriah’s, and tells Joab to keep fighting. He tries to reassure Joab.)