All these evil things come from within,.... All evil thoughts, words, and actions, take their rise from the inward parts of man; from his heart; which is sadly corrupted, and is the fountain from whence all these impure streams flow.
And if these come from within, then not from without; they are not by imitation or are the mere effects of example in others: example may indeed, and often does, draw out the evil that is within; but it does not produce it there; if it was not there before, it could not draw it out from thence: and if all these evils come from within, then the inward part of man must be sinful and polluted, previous to the commission of these evil things; and from whence springs then that inward pollution?
It is the fruit of original sin, of Adam's transgression; the consequence of which is, a corrupt nature, which is derived to all his posterity: for his nature being corrupted by sinning, and he having all human nature in him, the individuals of it could not be propagated by ordinary generation, without the pollution of sin cleaving to them; "who can bring a clean thing out of an unclean?