Jamieson, Fausset & Brown

As it is written, &c.-- (Psa 14:1-3; Psa 53:1-3). These statements of the Psalmist were indeed suggested by particular manifestations of human depravity occurring under his own eye; but as this only showed what man, when unrestrained, is in his present condition, they were quite pertinent to the apostle's purpose.