John Calvin's Bible Commentary
Jeremiah 47:1
Jeremiah prophesies here against the Philistines, who were enemies to the Israelites, and had contrived against them many cruel and unjust things. There is then no doubt, but that God intended to testify, by this prophecy, his love towards the Israelites, for he undertook their cause, and avenged the wrongs done to them. We hence perceive why God had predicted the ruin of the Philistines, even that the Israelites might know his paternal love towards them, as he set himself against their enemies; and thus he gave them a reason for patience, because it behooved them to wait until God fulfilled this prophecy.
And he points out the time, Before Pharaoh smote Aza, or Gaza. The ancient Gaza, as far as we can find out, was near the sea; but after it was destroyed, another was built, which is mentioned by Luke, (Acts 8:26;) it appears from heathen writers that it was a celebrated city and opulent. But they are mistaken who think that its name is derived from the Persic word “Gaza,” which means treasures; for they say, that when Cambyses led an army against Egypt, he left there his riches. But the word עזה, Oze, is a very ancient Hebrew word; and it is well known that the ע, oin, has been pronounced like our g; and this is the case as to other words, as for instance, Gomorrah, עמרה, the ע, oin, has the sound of ג, gimel; so also צער, Tsor, the Greek and Latin interpreters have rendered it, Segor. Then Gaza has not derived its name from treasures, but it is a Hebrew word, signifying fortitude or strength.
Now Jeremiah says, that he prophesied against the Philistines before Pharaoh smote that city, but he did not demolish it. But we see that the Prophet threatens nothing to it from the Egyptians, but rather from the Chaldeans. Why then does he speak here of Pharaoh?
We must refer to history, and then we shall see what the design of the Holy Spirit was. When Pharaoh came to bring assistance to the Jews under Zedekiah, as we have already seen, he was soon compelled to return to Egypt, for the Chaldeans, having raised the siege, went against the Egyptians; for if they routed them, they knew that they could soon possess themselves of the whole of Judea. Haying then left the Jews for a time, they went against the Egyptians. Pharaoh, possessing no confidence in himself, as I have said, retreated; but he plundered Gaza in his way, because it was very hostile to the Jews; and he wished to shew that he did not come altogether in vain, though this afforded no relief to the Jews. But thus in things of nought earthly kings shew off themselves. Pharaoh then at that time plundered Gaza, but he did not retain it. At this time Jeremiah predicted greater calamities. And this ought to be carefully noticed, for there would be no reason why the Prophet spake of the Philistines, except, he had respect to something farther. Let us now then come to the second verse: