The word of the LORD that came to Jeremiah the prophet against the Philistines, before that Pharaoh smote Gaza.
Before — In the time of the Philistines prosperity.
 Because of the day that cometh to spoil all the Philistines, and to cut off from Tyrus and Zidon every helper that remaineth: for the LORD will spoil the Philistines, the remnant of the country of Caphtor.
The day — Which God hath set, and appointed for their ruin.
Caphtor — Tyre and Sidon were neighbours to the Philistines, and so were often called to their help. The Philistines and Caphtorim were related, for their first progenitors, Philistim and Caphtorim, were both the sons of Mizriam the son of Ham, one of the sons of Noah.
 Baldness is come upon Gaza; Ashkelon is cut off with the remnant of their valley: how long wilt thou cut thyself?
The remnant — Those who lived in the valleys near Ashkelon.
But thyself — Why will you afflict yourselves, when all your mourning will do you no good.
 O thou sword of the LORD, how long will it be ere thou be quiet? put up thyself into thy scabbard, rest, and be still.
O thou sword — Perhaps they are the words of the prophet, lamenting the havock which he made among the Philistines by the Chaldeans.
 How can it be quiet, seeing the LORD hath given it a charge against Ashkelon, and against the sea shore? there hath he appointed it.
How — God lets the prophet know that he had given this sword its commission, and therefore it could not stop 'till Ashkelon and the people on the sea-shore were destroyed by it.