Peh's name means mouth, and a long tradition in Jewish letter-mysticism reads the letter's ordinary, open square-script shape as a figure for revealed, outward speech, in contrast with the separate closed final form used at the end of a word, discussed elsewhere in this atlas, which some commentators read instead as a figure for speech held back, concealed, or not yet spoken. That contrast between an open, forward-facing form and a closed, final one is not unique to Peh among the Hebrew letters, but Peh's own name makes the pairing unusually direct, since the ordinary letter's literal meaning already names the faculty, speech, that the shape is said to picture.
Because Peh is one of the Sefer Yetzirah's seven double letters, discussed elsewhere in this atlas, a sofer must also distinguish its hard p and soft f pronunciations by the presence or absence of a dagesh in vocalised texts, a linguistic distinction layered on top of, and independent from, the open-and-closed symbolism attached to its two written forms. Peh's literal meaning is old enough to predate the square script itself, carried over from the earlier palaeo-Hebrew writing that Jewish tradition holds the current alphabet replaced after the Babylonian exile, a transition discussed elsewhere in this atlas, and the letter's mouth-shaped meaning has stayed remarkably legible across that whole span of script reform, since a mouth is one of the easier human features to render in a simple line drawing. Later Kabbalistic literature sometimes extends the reading further, treating the five sofit letters as a group, discussed elsewhere in this atlas, as pointing collectively toward concealed matters.