Sforno on Genesis 20:11/ספורנו על בראשית כ׳:י״א

1רק אין יראת אלוקים במקום הזה, there is no respect for the government’s authority. The Philistines did not have kings, but their political leaders were known as סרנים, as we know from the story of Goliath, who was a law unto himself due to his personal strength and was not subject to the authority of such סרנים. Compare Goliath’s boast הלא אנכי הפלשתי ואתם עבדים לשאול, “am I not the Philistine, whereas you are slaves of Sha-ul.” (Samuel I 17,8)