The term heku (or hekau), in Ancient Egyptian mythology, refers to a type of magic or enchantment that Egyptian priests, sorcerers, and Pharaohs often performed. Heku is generally associated to vocalized forms, such as enchantments, songs, poems, and prayers. They may be found in the Egyptian book of the dead.
The energy is thought to derive from the powers of the gods Heka, Hu, and Sia. Generally, heku may be regarded as the Ancient Egyptian reverence for language and knowledge. That is, words were regarded as sacred, and thus their utterance was placed under the auspices of divination. The term can be seen to come up in common translations in Egyptology, such as in the term Werethekau, which may be translated as "she who has great magic." See Hathor, Sekhmet, and Aset.
Heku may be compared to the Kotodama of Asian cultures.