Basil of Caesarea, on Ps 61:4

"But they have thought to cast away my price; they ran in thirst: they blessed with their mouth but cursed with their heart." The price of [humanity's redemption] is the blood of Christ: "You have been bought," it is said, "with a price; do not become the slaves of people." The soldiers of Satan planned, therefore, to make this price useless to us, leading again into slavery those who had once been freed. "They ran in thirst." He is speaking of the eager plots of the demons, because they run against us, thirsting for our destruction. "They blessed with their mouth but cursed with their heart." There are many who approve evil deeds and say that the witty person is charming; the foulmouthed, statesmanlike; the bitter and irascible they name as one not to be despised; the miserly and selfish they praise as thrifty; the spendthrift, as bountiful; the fornicator and lewd, as one devoted to enjoyment and ease; and, in general, they gloss over every evil with the name of the proximate virtue. Such people bless with their mouth but curse with their heart. For by the auspiciousness of the words, they bring every curse on their life, making themselves liable to condemnation on the day of judgment because of those things that they approved.