Designs said:
Yetzer-tob and Yetzer ha-Rah, a little like Yin and Yang in Oriental philosophy
That's also a function that is associated with the kidneys, considered as the "decision-making" organs of the torso (of course, ancient Hebrews believed ALL cognition and thought took place in the organs of the torso, and NOT the brain (as indicated in Gen 8:21, YHWH talks about "thoughts in the HEARTS of men"; that's no figure of speech: the Hebrews literally believed that the heart played the role we know in modern times is carried out by the brain).
But back to kidneys: early Hebrews knew them to be paired organs, thinking one was one good and one, evil, which are consulted whenever one makes a decision (think of the classic "angel standing on one shoulder, the devil standing on the other" device still used in cartoons, etc). This explains why the kidneys and the associated fats were highly prized as a guilt-offering to YHWH, who considered the animal's kidneys as a good proxy for the penitant's own after making a poor decision.
This role of the 'kilyah' (kidneys, KJV reins) also explains why the Psalmist rhapsodizes in 139:13, " For thou hast possessedmy reinsthou hast coveredme in my mother'swomb ?????? ". Was he suggesting YHWH wanted to be a perinatal nephrologist, examining the fetus' urine-excreting organs, the kidneys, even before they functioned? Of course not: the Psalmist INTENDED to suggest that YHWH knew the decision-making capabilities of the fetus, i.e. his ability to exercise wisdom and good judgment later in life.
BTW, it's important to remember that Jews don't see the serpent in the Torahaic story as Satan: that's an interpretation inserted much later, to fit into the Messianic prophecies (eg Gen 3:15).
BTW, God's capacity for reading mens hearts is questionable, based on the justification given for the flood. This video points out God's flaw in judging characters, based on the Flood incident:
Terry, it takes exactly your approach, with a couple of product liability lawyers who try to place the blame solely with the manufacturer, God Almighty (video made by your's truly):