The evil inclination with its three layers resembles an almond. On the outside, there's a course shell. Once you break through that, there's a thin husk that clings to the meat of the nut. Yet on the inside, there's a fine biochemical – glycoside – that's dangerous, because the body breaks it down into cyanide. That's a metaphorical insight into the angelic evil inclination that wants us to do premature things that ultimately cause damage. They must be mitigated and purified.