Charles Ellicott Commentary 1 Samuel 23:8

"And Saul summoned all the people to war, to go down to Keilah, to besiege David and his men." — 1 Samuel 23:8 (ASV)

And Saul called all the people together. — Such a summons to war by the sovereign has always been a royal right. The justification, of course, alleged for this “summons” was the necessity of an immediate national effort against the hereditary enemies of the people.