Related to the verb weben (wbn), meaning "to rise", "rise in brilliance" or "shine" as well as ben-ben, the up thrust sacred stone of Heliopolis, benu (bennu) describes a bird that was an important avian deity. Originally of solar associations, the Benu bird came to be connected with three important gods consisting of Atum, Re and Osiris.
As an aspect of Atum, the Benu bird was said to have flown over the waters of Nun before the original creation. According to this tradition, the bird came to rest on a rock from which its cry broke the primeval silence and this determined what was and what was not to be in the unfolding creation.
The Benu, according to ancient Egyptian mythology, was also believed to be the ba of Re, and by Egypt's Late Period, the hieroglyphic sign depicting the bird was used to write the name of this sun god. During the Middle Kingdom, it was said that the Benu of Re was the means by which Atum came into being in the Primeval water.
Like the sun god, the Benu's own birth is attributed to self generation. A mythological papyri of the 21st Dynasty provides a vignette of a heart-amulet and scarab beetle near to which stand the Benu, which is described as "the one who came into being by himself". It was believed to constantly rise renewed just like the sun, and was called the "lord of jubilees". The Benu Bird was said to each morning appear under the form of the rising sun, and was supposed to shine upon the world from the top of the famous persea tree in Heliopolis wherein he renewed himself.
This most likely led to the concept of its long life, later identifying it with the Greek phoenix which also renewed itself from a fiery death like the sun rising at dawn. In fact, it may have been the prototype for the phoenix, and there may well be an etymological connection between the two birds' names, though certainly there are distinct differences between myths surrounding them.
The bird was primarily associated with Atum and Re, but inevitably, its connection with rebirth came to associate it also with Osiris. In quoting from the Book of the Dead, Wallis Budge quotes a passage that reads, "I go in like the Hawk, and I come forth like the Bennu, the Morning Star (i.e., the planet Venus) of Ra; I am the Bennu which is in Heliopolis" and he goes on to say that the scholion on this passage expressly informs us that the Benu is Osiris. In essence, the Benu was considered a manifestation of the resurrected Osiris.
Herodotus tells us that the bird lived for 500 years before building a nest of aromatic boughs and spices which it then set ablaze and was consumed within the inferno. From the conflagration a new Benu bird arose who, after embalming its father's ashes, flew with them to Heliopolis where it deposited the ashes on the altar of the temple of Re. However, this tale told by Herodotus has no foundation in actual pharaonic mythology, where the bird never seems to permanently die. There were, in fact, a number of classical interpretations of the Benu bird which resulted in a misunderstanding of the Egyptian myth, perhaps because of the association with the Egyptian bird and the Greek phoenix.
The yellow wagtail (Motacilla flava)
At Heliopolis where the Benu bird first served as a symbol of solar deities, its iconography was probably fashioned from the yellow wagtail (Motacilla flava) which, according to the Pyramid Texts, represented Atum. However, by the New Kingdom, the bird was usually depicted as a gray heron (ardea cinera). At that point in Egyptian mythology, it was usually represented with long legs and beak, and a two-feather crest growing form the back of its head. Typically, the bird surmounted a stylized ben-ben stone as a symbol of the great solar god, but its association with Osiris meant that it was also sometimes represented in the sacred willow of that god. Sometimes, it was also depicted wearing the Atef Crown in its aspect as Osiris. In at least, one the sarcophagus of the Divine Adoratrice of Amun, Ankhnesneferibre, now in the British Museum, the Benu is imagined as perched on a sacred willow tree in the temple. However, the Benu could also be depicted in a hybrid form with the head of a man. Classically, the Benu bird is described as being as large as an eagle, with red and gold (solar or flame-colored) plumage.
The Benu Bird with Atef Crown
The bird was frequently depicted in the vignettes of the netherworld books as well as on heart amulets and other objects, particularly those of a funerary nature. When carved on the back of a heart-scarab and buried with the dead, it is a symbol of anticipated rebirth in the netherworld and ensures that the heart does not fail in the examination of past deeds in the Hall of the Two Truths (judgment of the dead). In the Book of the Dead there are formulae to transform the deceased into the Great Benu. Here, the deceased says, "I am the Benu, the soul of Ra, and the guide of the gods in the Duat." In another verse, he says, "I am pure. My purity is the purity of the Great Benu which is in the city of Suten-henen."
Surprisingly little is known of the formal veneration of this important aspect of ancient Egyptian mythology. However, it is highly probable that it formed the basis for an important role in the cults near Heliopolis, where the cult was first established and probably most important. Wallis Budge tells us that "the sanctuary of the Bennu was the sanctuary of Ra and Osiris, and was called Het Benben, i.e., the 'House of the Obelisk'…" However, almost nothing else is known about the worship of the most ancient of Egyptian icons.