In Egyptian records the city’s name was written as Junu, while Assyro-Babylonian records mention it as Ana or Unu. The Egyptian name is thought to mean “City of the Pillar,” perhaps referring to the obelisks (tall, tapering columns topped by a pyramid-shaped point) for which the city was famous; or the name may relate to the sacred stone (called the benben) connected with the worship of the sun-god Ra (Re). The Greeks called the city Heliopolis, meaning “City of the Sun,” because it was the chief center of Egyptian sun worship.

The prophet Jeremiah was inspired to foretell that King Nebuchadnezzar would overrun Egypt and “break to pieces the pillars of Beth-shemesh, which is in the land of Egypt.” (Jer 43:10-13) Beth-shemesh corresponds somewhat to the Greek name Heliopolis and means “House of the Sun.” Hence the reference here is likely to the city of On, and “the pillars” that were to be broken may well refer to the many obelisks around the temple of the sun.

Ezekiel’s prophecy contains a similar warning. (Eze 30:10, 17) Here the Hebrew vowel pointing of the name varies from that of Genesis so that the name literally is Aven (Heb., ʼaʹwen). Some scholars suggest that this was done as a play on words, since Aven means “Hurtfulness; Something Hurtful,” and On was a center of idolatry.

This may also be the case at Isaiah 19:18, where the Masoretic text refers to one of the “five cities in the land of Egypt speaking the language of Canaan and swearing to Jehovah” as “The City of Tearing Down [Heb., ʽIr ha-Heʹres].” The Dead Sea Scroll of Isaiah has ʽIr ha-Cheʹres, meaning “City of the Sun,” thus pointing to On (Heliopolis). Here again there may be an intentional play on words, Heʹres (tearing down) being substituted for Cheʹres (another Hebrew word for “sun,” less common than sheʹmesh) in view of Jehovah’s intention to destroy the idolatrous city of On. The paraphrase of this portion of the verse found in the Aramaic Targums reads: “(City of) the House of the Sun, which is to be destroyed.”