Peh means mouth, speech, edge, or opening. It appears about 500 times. It refers to the physical mouth, the act of speaking, the edge of a sword, and the opening of a well or pit.
The mouth is the instrument of both blessing and cursing, truth and deception. God's mouth speaks creation into being and utters His law. 'Man shall not live by bread alone but by every word that comes from the mouth of God' (Deuteronomy 8:3) establishes God's speech as humanity's true sustenance.