[םמ] The thirteenth letter of the Hebrew alphabet, it symbolizes the element water (מים MayiM). Its Kabbalistic value is 40. Mem is one of the three mother letters (אמש).
Mem is the fountain of Divine Wisdom (Chokmah). Just as the waters of the well of Jacob (spring) ascend from its unknowable subterranean sources to unveil the mysteries of the tree of life on earth (Malkuth), likewise the fountain of Schamayim, the Superior Waters in Daath, unveil the wisdom (Chokmah) that express the power “Iod” or the flow of light from the Ain Soph.