Notes on the Bible, by Albert Barnes, , at sacred-texts.com
that Pharaoh - Pharaoh-Necho though defeated at Carchemish, was probably able to seize Gaza upon his retreat, when obviously the possession of so strong a fortress would be most useful to him to prevent the entrance of the victorious Chaldaeans into Egypt.
Waters rise up - A metaphor for the assembling of an army (compare the marginal references).
Out of the north - The Chaldaean army must cross the Euphrates at Carchemish.
An overflowing flood - Or, "torrent." To understand the metaphors of the Bible we must keep the natural phenomena of the country in mind. In Palestine rivers are torrents, dashing furiously along in the rainy seasons, and dry, or nearly so, in the summer.
All that is therein - The marginal rendering contrasts the wealth of Egypt, which forms its fullness, and the inhabitants.
His strong horses - War-horses, chargers.
The rushing of his chariots - Rather, the rattling, the crashing noise which they make as they advance.
For feebleness of hands - The Philistines flee in such panic that a father would not even turn round to see whether his sons were effecting their escape or not.
Because of the day that cometh to spoil - "Because" the day has come "to devastate."
The Philistines are called Tyre's remaining (i. e., last) helper, because all besides who could have assisted her have already succumbed to the Chaldaean power. The judgment upon Philistia was in connection with that upon Tyre, and it was fulfilled by expeditions sent out by Nebuchadnezzar under him lieutenants to ravage the country and supply his main army with provisions.
The country of Caphtor - The coastland of Caphtor. The Philistines came from the coast of the Egyptian Delta, and are called "a remnant" because they had been greatly reduced in numbers, partly by the long war of Psammetichus against Ashdod, partly by the capture of Gaza Jer 47:1, and partly by Assyrian invasions.
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 Sa1 17:4.
Jer 47:6. Or, Alas, Sword of Yahweh, how long wilt thou not rest? For the answer, see Jer 47:7.