Charles Ellicott Commentary 2 Samuel 1:12

"and they mourned, and wept, and fasted until even, for Saul, and for Jonathan his son, and for the people of Jehovah, and for the house of Israel; because they were fallen by the sword." — 2 Samuel 1:12 (ASV)

They mourned. —On hearing the news from the Amalekite, David and all his people showed the usual Eastern signs of sorrow by tearing their clothes, weeping, and fasting. Although David thus learned of the death of his persistent and mortal enemy, and of his own resulting accession to the throne, yet there is not the slightest reason to doubt the reality and earnestness of his mourning. The whole narrative shows that David not only, as a patriotic Israelite, lamented the death of the king, but also felt a personal attachment to Saul, despite his long and unreasonable hostility.

But Saul did not die alone; Jonathan, David’s most cherished friend, fell with him. At the same time, the whole nation over which David was to reign in the future received a crushing defeat from their foes, and large numbers of his countrymen were slain. It has been well remarked that the only deep mourning for Saul, with the exception of the men of Jabesh-gilead, came from the man whom he had hated and persecuted as long as he lived.

The people of the Lord. —Besides his personal grief, David had both a religious and a patriotic reason for sorrow. The men who had fallen were parts of that Church of God which he so earnestly loved and served, and were also members of the commonwealth of Israel, for whom he always labored with patriotic devotion. The Septuagint, overlooking this distinction, has very unnecessarily changed people of the Lord into people of Judah.