The Benben Stone enters the written record in the Pyramid Texts, carved into the walls of the pyramid of King Unas at Saqqara around 2400 BCE and preserved in the pyramid of Pepi II a century later. In Utterance 600, the text addresses Atum, the creator god of Heliopolis: "Atum Kheprer, you have come to be high on the hill, you have arisen on the Benben stone in the mansion of the Bennu in Heliopolis, you spat out Shu, you expectorated Tefnut, and you put your two arms around them as the arms of a Ka symbol, so that your ka might be in them." This is the Heliopolitan creation myth in its earliest form: before the world existed, there was only Nun, the dark primordial waters that stretched infinitely in every direction, the chaos from which all order would emerge. From those waters rose the Benben, the first mound of dry land, and upon it appeared Atum, the self-created god who needed no parents, who generated himself from his own substance. Atum spat out Shu, the god of air, and expectorated Tefnut, the goddess of moisture, and the embrace of these two children held up the sky and created the space within which the world could exist. The Benben was thus the physical anchor of creation, the point where the infinite waters gave way to finite land, where chaos surrendered to order, where nothing became something.

The Benben stone was more than a mythological concept. It was a physical object, a sacred stone that stood in the temple of Ra at Heliopolis, the city called Iunu or Annu by the Egyptians, the centre of solar worship and the most important religious city in the land. The stone was the focus of the temple's cult, the place where the first rays of the rising sun fell each morning, and it was associated with the Bennu bird, the sacred heron that the Egyptians believed perched upon it and whose cry initiated the act of creation. The Egyptologist Barry Kemp has proposed that the whole cluster of ideas may rest on a chain of Egyptian wordplay: the sun rises, weben, throwing its light onto the benben, on which the bennu perches - three words, one dawn, the sound of creation itself encoded in the language.

The shape of the Benben stone is debated. From the earliest times, the portrayal of Benben was stylised in two ways: the first was as a pointed, pyramidal form, which was probably the model for pyramids and obelisks. The other form was round-topped, which was probably the origin of Benben as a free-standing votive object and an object of veneration. During the Fifth Dynasty, the portrayal was formalised as a squat obelisk, and later, during the Middle Kingdom, this became the long, thin obelisk that still stands in Egyptian temple complexes. The capstone of every pyramid, called the pyramidion or benbenet, was modelled directly on the Benben stone, and these gleaming stones were often sheathed in gold or electrum, a natural alloy of gold and silver, so that they caught the morning sun and flashed like beacons across the desert. The pyramidion of Amenemhat III from the Black Pyramid at Dahshur, now in the Egyptian Museum in Cairo, is one of the finest surviving examples: carved with winged solar disks, Eyes of Horus, royal cartouches, and protective hieroglyphs, it is the Benben made permanent in stone.

The Benben stone's influence extended beyond architecture into the very structure of Egyptian kingship. The pharaoh was the living Horus, the son of Osiris and Isis, and in death he would become an Osiris himself, ascending to join the sun god Ra in his daily journey across the sky. The pyramid, with its benbenet capstone, was the physical mechanism of this ascent: the dead king's spirit would rise through the pyramid's passages and emerge from its pointed summit into the light of the dawn, just as Atum had emerged from the waters upon the Benben. The obelisk served the same function in temple architecture, a single shaft of stone topped with a pyramidion, standing before the temple as a permanent Benben that renewed the act of creation with every sunrise. When the obelisk was sheathed in electrum, the morning sun struck its peak and the whole shaft blazed with reflected light, a pillar of fire that connected earth and heaven.

The original Benben stone was lost in antiquity, and its nature remains a subject of scholarly speculation. Some Egyptologists have proposed that it may have been an iron meteorite, a fragment of celestial iron that fell from the sky and was venerated for its otherworldly origin. The conical or pyramidal shape of oriented iron meteorites, which form a distinctive cone as they tumble through the atmosphere, matches the pointed form of the Benben, and the Egyptians did prize meteoric iron for sacred objects. The Gerzeh iron beads, discovered in a tomb near Cairo and dated to around 3200 BCE, were confirmed in 2013 to be made from meteoric iron, proving that the Egyptians knew of and worked with metal from the sky long before they learned to smelt iron ore. Whether the Benben was a meteorite, a natural stone, or a carved cult object, its power lay not in its material but in its meaning: it was the first thing, the original mound, the place where the world began.

The Bennu bird, the heron of Heliopolis, was inseparable from the Benben in Egyptian thought. The bird was understood as the ba, the soul, of Ra, the sun god, and its daily rising with the sun made it the living emblem of renewal. In the Heliopolitan creation story, the Bennu flew over the waters of Nun and landed on the Benben, and its first cry broke the silence of the beginning. The Greeks, encountering this bird at Heliopolis, called it the phoenix, and Herodotus, writing in the 5th century BCE, recorded that the phoenix lived five hundred years before carrying its dead parent, encased in an egg of myrrh, to the sun temple at Heliopolis for burial. The famous self-cremation of the phoenix, bursting into flame and rising from its own ashes, was a later Greek and Roman addition; the Egyptian Bennu renewed itself the way the sun renewed itself, rising fresh each dawn without death or destruction. The connection between bird and stone was so close that the temple at Heliopolis was called the Mansion of the Bennu, and the Benben stood at its heart.