John Calvin Commentary Zechariah 9:6

"And a bastard shall dwell in Ashdod, and I will cut off the pride of the Philistines." — Zechariah 9:6 (ASV)

In this verse, the Prophet denounces a similar ruin upon Azotus and the whole land of the Philistines, or upon the whole land of Palestine. For what some interpreters say—that the Jews would dwell at Azotus as strangers (meaning, though they had previously been considered foreigners)—is completely wide of the mark.

The Prophet, on the contrary, means that after the destruction of these cities, if any inhabitants remained, they would be like strangers, without any secure dwelling. The Prophet then mentions the effect to show that the country would be waste and desolate, so that it would contain no safe or permanent dwellings for its inhabitants.

Some translate the word as 'spurious,' as it is translated in some other places, and they understand this as referring to the Jews, because they had previously been in a lowly condition, as if they were an illegitimate race. However, the opinion of those who derive ממזר (memezar) from זור (zur), which means 'to wander' or 'to sojourn,' is probable. They quote other instances in which the double ממ (mem) is used in the formation of a noun, and it is easy to prove from many passages of Scripture that ממזר (memezar) means 'a stranger'.

And if anyone carefully considers the Prophet's purpose, they will see the truth of what I have said—namely, that his object is to show that all the inhabitants of Azotus and of the land of the Philistines would be like sojourners, because all places would be desolate through the slaughter and devastations of enemies. Since Ashdod and Palestine had previously been known for their large populations, the Prophet says that all the cities of Palestine, and the city of Ashdod, would be deserted, except that a few scattered and wandering inhabitants would remain there, like those who sojourn in a foreign land.