Let not this thing displease thee; be not dejected or discouraged by this sad occasion. Encourage thou him, i.e. Joab, to proceed in the siege.
Related Commentaries of 2 Samuel 11:25
2 Samuel 11:25
25 Then David said unto the messenger, Thus shalt thou say unto Joab, Let not this thing displeasee thee, for the sword devoureth one as well as another: make thy battle more strong against the city, and overthrow it: and encourage thou him.