But the hand of Yahweh was heavy on them of Ashdod, and he destroyed them, and struck them with tumors, even Ashdod and the borders of it.
The Hebrew word translated "broke out" occurs only here in the Old Testament (1 Samuel 5:9). The Septuagint translators interpreted it accurately as "groin." These tumors were apparently most prominent in the groin area, hence the English translation "hemorrhoids." Tumors in the groin are a symptom of bubonic plague. Since the Philistines associated mice with this plague (1 Samuel 6:4-5), and mice carry bubonic plague, it seems clear that the hand of Yahweh sent this particular affliction on them.