Deliverers and Judges: Ehud - From Ancient Chinese, Japanese and Jewish slavery

John Gill Commentary

Judges 3:12
And the children of Israel did evil again in the sight of the Lord,.... Fell into idolatry again, which was a great evil in the sight of God, and what they were prone to fall into:
and the Lord strengthened Eglon the king of Moab against Israel; put it into his heart to invade them, and encouraged him to it, and gave him success; what kings reigned over Moab between Balak and this king we know not: it is a commonly received notion of the Jews, that Ruth was the daughter of Eglon; see Rth_1:4; and it was about this time that Elimelech with his two sons went into Moab, and when many of those things recorded in the book of Ruth were transacted:
because they had done evil in the sight of the Lord; which had greatly provoked him to anger, and was the cause of stirring up the king of Moab against them.