12 And till evening they gave themselves to sorrow and weeping, and took no food, weeping for Saul and for Jonathan, his son, and for the people of the Lord and for the men of Israel; because they had come to their end by the sword.

Matthew Henry's Commentary on 2 Samuel 1:12

Commentary on 2 Samuel 1:11-16

(Read 2 Samuel 1:11-16)

David was sincere in his mourning for Saul; and all with him humbled themselves under the hand of God, laid so heavily upon Israel by this defeat. The man who brought the tidings, David put to death, as a murderer of his prince. David herein did not do unjustly; the Amalekite confessed the crime. If he did as he said, he deserved to die for treason; and his lying to David, if indeed it were a lie, proved, as sooner or later that sin will prove, lying against himself. Hereby David showed himself zealous for public justice, without regard to his own private interest.