הלכה על מכות 3:5

To not destroy the corner of the beard: To not destroy the corner of the beard, as it is stated (Leviticus 19:27), "and you shall not destroy the corner of your beard." And there are five corners to the beard, and there is a [separate] liability for lashes for each one, even if he removed them all at once and with one warning. And these are them: the upper and lower jaw on the right; the upper and lower on the left - behold, that is four - and the chin of the beard, and that is the place of connection of the jaws below, which is called menton in the vernacular - behold, that is five. And the language of the Mishnah (Mishnah Makkot 3:5) is "For the beard, five: two from here and two from there and one at their bottom." And the transcriber wrote in the name of Rambam, may his memory be blessed, (on Sefer HaMitzvot LaRambam, Mitzvot Lo Taase 44), "And the prevention came about this with these words, 'and you shall not destroy the corner of your beard,' and it did not say, 'and you shall not destroy your beard' - even though it is all called the beard. It wanted to say with this that you should not shave even one corner from the whole of the beard. And we administer one [set of] lashes for each one. And even if he shaved all of them at one time, he is liable five [sets of] lashes for it."