In ancient Egypt, the term house of eternity refers to a tomb that consists of a pit, a tomb shaft, or from mudbricks, which were later carved into rocks; or built on open land. Burial sites made of stone were a "sign of immortality", due to the long durability of stone. This was an ideal construction method that could be afforded by only a very few ancient Egyptians, due to its high cost. In ancient Egyptian mythology, the construction of a monument during one's own lifetime represented the most intensive representation with the connection of life; and the concept of living in the afterlife.
The house of eternity was "a place to meet oneself" for the tomb owner and contained decorations portraying the owner's likeness, and the stages of their lives. The owner immortalised themselves with their portrait on the walls of the tomb, along with the inscriptions, to resurrect them in "a new life in later times". The tomb owner depicted their "completed life" in anticipation of their death, which according to their beliefs, was to be removed from this form; in the portrayal of oblivion and mortality.
The tomb owner hoped that through immaculate moral conduct, they would meet their Ka in the afterlife. The house of eternity was the place that enabled the tomb owner to endure unwavering, in the 'eternal life' (djet). With that said, the ancient Egyptians began to spend the most important annual celebrations in the house of eternity.
Mythological connections
The ancient Egyptians believed that life in the mortal world was short in comparison to eternity in the afterlife. They, therefore, had two concepts of time for 'the eternal cycle of life of earth' (neheh – nḥḥ) and 'life in the eternity of the kingdom of the dead' (djet – ḏt). 'Neheh' means a period of time in which something exists, renews and repeats. 'Djet' refers to the future in which earthly life will have ended and everything accomplished in life lives for an indefinite amount of time in Duat.
The sun god Ra was the manifestation of the time called 'neheh', as Ra 'renewed himself every night' and 'was reborn' with the dawn of every day by the sky goddess Nut. Contrary to this, Osiris, as the god of the dead, was the synonym for the time called 'djet'. Osiris', whose appearance was as a mummy, also carried the name of; 'the one who continues to be perfect.' In this respect, neheh, the time of Ra, is the rebirth, and djet, the time of Osiris, is the remembrance.The 'life goals' of the ancient Egyptians depicted the eternal continuation in the 'Kingdom of Osiris', for which the embalming, mummification and the reading of the judgment of the dead; were required for those who had died. A life lived in moral perfection symbolised 'the good', which was allowed to pass into the afterlife and thus, in the djet after being 'checked by the judgment of the dead.' The house of eternity also functioned as the 'tribunal and mummification hall', constructed according to the principles of the goddess Maat.
The house of eternity as the 'book of life'
The ancient Egyptians lead their lives from birth in preparation for later death. The officials with good earnings and the people working in the temple cults began planning their own house of eternity upon entering into working life. Reserve funds, built from their income, were used for the gradual expansion of their tombs. After laying the foundation stone, the inscriptions telling the stages of life followed. The tradition of the ancient Egyptian house of eternity had its roots in 'result-oriented thinking', which was based on past culture and had no scope for innovation at the religious level.
Contrary to the spiritually innovative progress, which took into consideration life experiences and the further course of continually adapting to new circumstances, the Egyptians saw personal life until death as a perfect outcome for the preparation of the afterlife; in which the completed actions on earth would be repeated. The actions 'to be repeated' had their spiritual foundation in the cult of the dead, which prescribed to living a morally perfect life. Upon the 'successful accomplishments of the tasks in life', the beckoning reward after death was the 'crossing into the holy land.' The point of departure for the crossing into Duat was the house of eternity. Therefore, the construction and the orientation for the tomb was the most important project in the life of an ancient Egyptian.