Charles Ellicott Commentary Jeremiah 47:5

"Baldness is come upon Gaza; Ashkelon is brought to nought, the remnant of their valley: how long wilt thou cut thyself?" — Jeremiah 47:5 (ASV)

Baldness is come upon Gaza. —This baldness is the outward sign of extreme mourning (Jeremiah 48:37; Isaiah 15:2–3), perhaps also of extreme desolation (Isaiah 7:20).

Ashkelon is cut off ... —It is perhaps better rendered, Ashkelon is speechless. The Septuagint apparently followed a different text, and gives “the remnant of the Anakim” instead of “the remnant of their valley.” Hitzig adopts this rendering, and connects it with the known fact that a remnant of the old gigantic non-Semitic race had taken refuge among the Philistines (1 Samuel 17:4; 2 Samuel 21:22; 1 Chronicles 20:5–8) after they had been driven from Hebron (Joshua 14:12–15; Joshua 15:13–14).

Others, without adopting the Septuagint reading, interpret the word rendered “their valley” as meaning, as in Isaiah 33:19, those who speak an unintelligible language, barbarians (Amakim), and suppose this form passed in the Septuagint into the more familiar form of Anakim.

The English version, however, is accepted by many critics, and may refer to Ashkelon and Gaza as the “remnant,” the last resource of the valley (Emek) or low-country of the Philistines, more commonly known as the Shephelah.

How long wilt thou cut thyself? —These words point to a ritual of supplication, like that of the priests of Baal in 1 Kings 18:28, as prevailing among the Philistines.