Zephaniah mentions four of the five main Philistine cities in this verse, leaving out Gath. It is not certain why this is so, though this was common among the prophets (Jeremiah 25:20; Amos 1:6–8; Zechariah 9:5–7). Its absence from the list is likely due to either its destruction by this time (Amos 6:2; 2 Chronicles 26:6) or its close association with Israel in its history (e.g., 1 Samuel 27:1–7).1,2
4 For Gaza shall be deserted, and Ashkelon shall become a desolation; Ashdod’s people shall be driven out at noon, and Ekron shall be uprooted.