Thomas Aquinas, on Ps 16:10

“They have shut up their fat: their mouth hath spoken proudly.”

“Next he sets forth the manner; hence he says, "Their fatness." Fatness in Scripture is sometimes taken in a good sense, sometimes in a bad sense. In a good sense, insofar as it signifies devotion of mind: Ps. 62: "Let my soul be filled as with marrow and fatness." In a bad sense: first, insofar as it signifies wickedness of heart; second, of mouth; third, of deed. And therefore it designates detestable malice: Job 21: "The bowels of the wicked are full of fat, and his bones are moistened with marrow." And this is manifold. Sometimes it is delight in the sin they commit: Prov. 2: "They rejoice when they have done evil and exult in the worst things." Also pride and falsehood: Job 11: "A vain man is puffed up with pride and thinks himself born free, like the colt of a wild donkey." Also carnal sensibility. He says, therefore, "Their fatness," that is, their carnal sense, or pride, or delight, "they have shut up" within themselves, so as not to grasp the spiritual sense. Jerome has, "With their fat," that is, with the abundance of temporal goods and worldly power, "they have enclosed me." Second, regarding the mouth: "Their mouth has spoken pride." And this is when the Jews spoke against Christ: Mt. 27: "If you are the King of Israel," etc.”

Imported from an open dataset — not yet checked against the printed edition.