In Vayikra 19:27, the Passuk says ולא תשחית את פאת זקנך - "and you shall not destroy the edge of your beard". I believe it says in Meseches Makkot (3:5) that this Passuk refers to 5 edges of the beard (or something to that effect).
- Do we know where these 5 edges are?
- Where are they?
- Are there any places on the face that we know can definitely be shaved by a razor?