Ellicott's Commentary On The Whole Bible
2 Samuel 1 - Introduction
At the moment when this book opens, the events narrated in 1 Samuel 31 were not known to David. At the time of the fatal battle between Saul and the Philistines, David had been engaged in his successful attack upon the Amalekites who had spoiled Ziklag (1 Samuel 30) and it was not until two days after his return (2 Samuel 1:2) that the news reached him.