Hebrew זֶרֶת. Literally "a spread hand". Also called Zeret.
Thumb-tip to little-finger-tip on a spread hand: half a cubit.
Length
22.2–22.9 cm (8.75–9 in).
Defined as 1/2 of a cubit.
Inherits the disagreement over the cubit.
The span is the width of an outstretched hand, and it is exactly half a cubit. It is the measure the high priest's breastpiece is given in — a span square — and it is the second half of Goliath's height, which the text gives as six cubits and a span rather than rounding.
The Hebrew text of 1 Samuel 17:4 gives Goliath’s height as six cubits and a span, and a span is half a cubit. It is drawn here with an 18-inch cubit. A Hebrew copy of Samuel among the Dead Sea Scrolls, and the ancient Greek translation, read four cubits and a span instead: a very tall man rather than a giant. The weights use this Almanac’s shekel.