Baldness - Extreme mourning (see Jer 16:6).
Is cut off - Others render, is speechless through grief.
With the remnant of their valley - Others, O remnant of their valley, how long wilt thou cut thyself? 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 1Sa 17:4.
Jer 47:6. Or, Alas, Sword of Yahweh, how long wilt thou not rest? For the answer, see Jer 47:7.