Adam Clarke on Nehemiah 9:25

Became fat, and delighted themselves - They became effeminate, fell under the power of luxury, got totally corrupted in their manners, sinned against all the mercies of God, and then were destroyed by his judgments. We have an old nervous saying, "War begets poverty, poverty begets peace, peace begets affluence, affluence begets luxury and corruption of manners; and hence civil broils, foreign wars, and desolations." A sensible Roman historian has said the same: "Imperium facile iis artibus retinetur, quibus initio partum est: verum ubi pro Labore, Desidia; pro continentia et aequitate, Libido atque Superbia invasere: fortuna simul cum moribus Immutatur."