ON (city) ŏn (אֹ֖ן, אֹֽון; pillar-city), capital of the thirteenth nome of Lower Egypt, about six m. NE of Cairo and three m. N of modern Heliopolis.
Religious and intellectual center. From the earliest times On was a center for the worship of the sun-god. The walls (now below ground) of the great temple area measure about 540 ft. by 1,375 ft., and within these walls were temples of the sun at Atum, Ra-Harakhte, and Hathor. Sacred to the sun was the bnbn stone, a small, primitive obelisk; a sacred išd tree; and the crested heron, called phoenix by the Greeks (Herodotus II. 73). The bull-god Mnevis also was worshiped at On, and his sacred pillar, the iwn, gave the city its name. The priests of Heliopolis were reputed to be the most learned in Egypt (Herodotus II.3) They studied astronomy and philosophy, and the Gr. philosophers Plato and Eudexus are said to have learned from them (Strabo XVII. 1. 29). The chief priest had the title “Greatest of Seers,” the office and title which Joseph’s father-in-law prob. held.
Visit of the Holy Family. According to the medieval Arabic [[Gospel of the Infancy]], 24, the Holy Family, in their flight to Egypt (Matt 2:14, 15), visited al-Maṭariyah, which occupies part of the site of On, and took shelter under a sycamore tree. A sycamore there, traditionally identified with this tree, recently died at the age of about 300 years, and both Christians and Muslims still revere its gnarled trunk.
W. M. F. Petrie, Heliopolis, Kafr Ammar, and Shurafa (1915); B. Porter and R. L. B. Moss, Topographical Bibliography of Ancient Egyptian Hieroglyphic Texts, Reliefs and Painting, IV (1934); A. H. Gardiner, Ancient Egyptian Onomastica, II (1947); H. Bonnet, “On,” Reallexikon der ägyptischen Religionsgeschichte (1952), 543-545; A. Rowe, “The Famous Solar-City of On,” PEQ, XCIV (1962), 133-142; O. F. A. Meinardus, In the Steps of the Holy Family from Bethlehem to Upper Egypt (1963).