The thought of foolishness is sin - חטאת אולת זמת zimmath ivveleth chattath . "The device of folly is transgression;" or, "an evil purpose is sinful;" or, perhaps more literally, "the device of the foolish is sin." It has been variously understood by the versions.
"The cunning: of the fool is sin."
- Targum.
"The imprudent man (or fool, αφρων ) shall die in sins."
- Septuagint.
So the Arabic.
The thinkynge of the fool is synne
- Old MS. Bible.
Fool is here taken for a wicked man, who is not only evil in his actions, but every thought of his heart is evil, and that continually. A simple thought about foolishness, or about sin itself, is not sinful; it is the purpose or device, the harbouring evil thoughts, and devising how to sin, that is criminal.