Nahum 3:4 - Joseph Benson’s Commentary on the Old and New Testaments

Because of the multitude, &c. That is, this judgment is executed upon Nineveh because of the multitude of her whoredoms, by which idolatrous rites seem to be meant, for they are generally called whoredoms in the Scripture. Nineveh is called a well-favoured harlot, because, by her example and influence, she drew in other places to practise the same idolatries and other vices of which she was guilty. That selleth nations through her whoredoms That makes whole nations a prey to their enemies, by encouraging them to worship idols, and thereby exposing themselves to the wrath of God: or by teaching them the arts of softness and effeminacy, and so rendering them weak and defenceless. As the violence and injustice of the Ninevites had been represented under the emblem of a lion, the prophet here paints their irregularities, their idolatry, and corruption, under the idea of a prostitute enticing men to commit lewdness.