Albert Barnes 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 – Extreme mourning .

Is cut off – Others render, is speechless through grief.

With the remnant of their valley – Others, O remnant of their valley, how long will you cut yourself? Their valley is that of Gaza and Ashkelon, the low-lying plain, usually called the Shefelah, which formed the territory of the Philistines. The reading of the Septuagint is remarkable: “the remnant of the Anakim,” which probably would mean Gath, the home of giants (1 Samuel 17:4).

Jeremiah 47:6. Or, Alas, Sword of Yahweh, how long wilt thou not rest? For the answer, see Jeremiah 47:7.