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Cubit

Hebrew אַמָּה. Literally "forearm". Also called Ammah, Forearm.

Elbow to fingertip — the everyday measure of building, and the one nearly every other length is stated in.

Length (common)
44.5–45.7 cm (17.5–18 in). Reckoned from the Siloam tunnel inscription, and surviving rods from Egypt. Estimates run from about 44.5 cm to 45.7 cm for the ordinary cubit.
Length (royal)
51.8–52.5 cm (20.4–20.7 in). Reckoned from Ezekiel's "a cubit and a handbreadth". The long cubit is about a seventh longer. Ezekiel measures the temple with it; most narrative does not.

A cubit is a forearm, which is why it is approximate by nature: it began as a body measure and was standardised differently in different places and centuries. Two lengths are in play in the Old Testament. The ordinary cubit runs about 44–46 cm, and the Siloam tunnel — cut under Jerusalem around 700 BC and recorded in its own inscription as 1,200 cubits long — is the best check on it. A longer royal cubit of about 52 cm also appears, and Ezekiel is explicit that he is using it: his cubit is "a cubit and a handbreadth". The difference is not academic. Noah's ark at 300 cubits is 133–137 m long on the ordinary cubit and 155–158 m on the long one.

Noah’s ark, drawn to scale A side view and an end view of the ark as Genesis 6:14–16 describes it: 300 cubits long, 50 wide and 30 high, which is 437–450 ft by 72.9–75 ft by 43.8–45 ft (133–137 m by 22.2–22.9 m by 13.3–13.7 m). It has a roof, a door in its side with a ramp, and three levels, sealed with pitch. A man 6 feet tall stands under the bow, shown again twelve times larger in a magnifier. 300 cubits437–450 ft · 133–137 m 30 cubits43.8–45 ft13.3–13.7 m a roof, finished to a cubit upward gopher wood, three levels,sealed with pitch inside and out the door, set in its side a 6-ft (1.8 m) man, 12× largerto scale, he is the speck under the bow 50 cubits72.9–75 ft · 22.2–22.9 m END VIEWalmost as wide as atennis court is long (78 ft) SCALE 01020304050m 050100150ft
Genesis 6:15 gives the ark as 300 by 50 by 30 cubits. It is drawn here with an 18-inch cubit: roughly one and a half American football fields long, not counting the end zones, and four storeys high.

Disputed. No standard rod survives from Israel. Reconstructions rest on the Siloam tunnel, on Egyptian and Mesopotamian rods, and on rabbinic tradition, and they differ by up to 18%.

Where it appears

See also

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