Cubit

The cubit (Hebrew ammah, Latin cubitus, 'elbow') was the universal length unit of the ancient Near East, measured from the point of the elbow to the tip of the middle finger. Standard ('short') cubits ran about 44.5 cm; the so-called royal or 'long' cubit added a hand-breadth, giving roughly 52.5 cm (Ezekiel 40:5, 43:13). Egypt, Babylon, and Israel all kept official cubit-rods — carved wooden or stone bars graduated into fingers, palms, and spans — against which everyday measuring sticks could be calibrated. The cubit measured Noah's ark (300 × 50 × 30 cubits, Genesis 6:15), the Tabernacle and the dimensions of the Temple, Solomon's bronze sea (1 Kings 7:23), and the height of Goliath (6 cubits and a span, 1 Samuel 17:4 — about 2.9 metres in the standard Hebrew text, though some manuscripts read 4 cubits). Jesus uses the cubit metaphorically in Matthew 6:27 — none of you, by worrying, can add a single cubit to your lifespan — playing on its sense as a measure of both length and (here) a span of life.