Albert Barnes Commentary 2 Samuel 1:20

"Tell it not in Gath, Publish it not in the streets of Ashkelon; Lest the daughters of the Philistines rejoice, Lest the daughters of the uncircumcised triumph." — 2 Samuel 1:20 (ASV)

Gath was the royal city of Achish (1 Samuel 21:10; 1 Samuel 27:2). Ashkelon was the chief seat of worship (see the note on 1 Samuel 31:10).