The mouth, the letter pei, follows the eye, the letter ayin. The five kindnesses and five mights of the right and left eyes discussed in the letter ayin are in fact the dual manifestations of the sefirah of da'at, knowledge, as taught in Kabbalah. Da'at is the power of union and communication. Providence is the power of da'at as revealed by the eyes. The power of da'at as revealed by the mouth - speech - is the more explicit form of contact and communication between individuals. Just as in the verse: "and Adam knew his wife Eve," "knew," the power of da'at, refers to the physical union of man and wife, so is "speech" idiomatically used by our Sages to refer to such union. So are we taught in the Zohar: "[the power of] da'at is concealed in the mouth."
Da'at, contact, at the level of the eyes, is the secret of the written Torah. In reading the written Torah in the synagogue service the reader must see every letter of the Torah scroll. Sometimes a "silver finger" is used to point, direct one's sight, to every word. Contact at the level of the mouth is the secret of the Oral Torah.
"There is no good other than Torah." The pei is the seventeenth letter of the alef-beit, the numerical value of the Hebrew word tov, "good," as discussed at length in the letter tet. The first words spoken by the "Mouth" of God, "Let there be light," upon spontaneously being realized as the actual creation of light, were subsequently seen, by His "Eyes," "to be good." The word "good," is the thirty-third word of the Torah, the sum of the ordinal values of the two letters ayin and pei (33 = 16 plus 17), thus alluding to the union of the two levels of da'at, contact (that of the eyes, the written Torah, and that of the mouth, the Oral Torah).
Of the people of Israel it is said: "You are my witnesses, says God" and "God's testimony is within you." With closed eyes we testify twice every day: "Hear, O Israel, God is our God; God is one." The ayin of the first word, Shema, "hear," and the dalet of the last word, echad, "one," are written large. Together they spell the word eid, "witness." The soul of every Jew is an "eye"-witness to the essential unity of God. In this world we must close our physical eyes in order to reveal the inner eye of Israel which beholds the Divine Unity. By proclaiming our testimony verbally, we unify the two levels of contact, that of eye and that of mouth.
Expression of wisdom proceeds from the inner eye of the heart to the mouth, as is said: "the heart of the wise informs his mouth." Words of wisdom, when expressed sincerely and humbly by the mouth, find favor and grace in the eyes of God and man, as is said: "the words of the mouth of the wise find favor." In Sefer Yetzirah we are taught that the "gift" to the holy mouth is grace. In good ("There is no 'good' other than Torah") are inherent two essential properties: truth and grace. Though each dimension of Torah expresses the interinclusion of both of these properties, nonetheless, in particular, truth (the "male figure," primarily defined by the sefirot of "tiferet" and yesod in Kabbalah) is the primary consciousness of the written Torah, whereas grace (the "female figure," malchut) is that of the Oral Torah. The power of the pei, the mouth, is thus to express the grace of the Oral Torah.
A mouth containing a tooth.
The white space within the pei forms a hidden beit.
mouth; here (present)
Eighty; yesod - the power of marriage.