4. For--He makes the punishment awaiting the neighboring states an argument why the ungodly should repent (Zep 2:1) and the godly persevere, namely, that so they may escape from the general calamity.
      Gaza shall be forsaken--In the Hebrew there is a play of similar sounds, Gaza Gazubah; Gaza shall be forsaken, as its name implies. So the Hebrew of the next clause, Ekron teeakeer.
      at the noonday--when on account of the heat Orientals usually sleep, and military operations are suspended (2Sa 4:5). Hence an attack at noon implies one sudden and unexpected (Jer 6:4, 5; 15:8).
      Ekron--Four cities of the Philistines are mentioned, whereas five was the normal number of their leading cities. Gath is omitted, being at this time under the Jews' dominion. David had subjugated it (1Ch 18:1). Under Joram the Philistines almost regained it (2Ch 21:16), but Uzziah (2Ch 26:6) and Hezekiah (2Ki 18:8) having conquered them, it remained under the Jews. Am 1:6; Zec 9:5, 6; Jer 25:20, similarly mention only four cities of the Philistines.

JFB.