753. The Size of Various Measurements

Shabbos 17:36

A fingerbreadth in the context of measurements means the width of a thumb. A handbreadth is four fingerbreadths. A cubit, whether used regarding Shabbos, succah, or planting mixed species, means a cubit of six handbreadths. Sometimes a cubit means six handbreadths pressed close together and sometimes it means six handbreadths spaced loosely from one another. In either case, the cubit utilized was selected to arrive at the more stringent conclusion. For example, the length of an alley must be at least four cubits; this is measured using loosely-spaced cubits. The height of an alley may not exceed twenty cubits; this is measured using tightly-spaced cubits. Similarly, the length of an entrance may not exceed ten cubits measured using tightly-spaced cubits. The same principle applies to the laws of succah and to the laws of planting mixed species.

Shabbos 18:1

One who transfers something from a private domain to the public domain or vice versa is not liable unless he transferred a useful volume of that thing. The minimum volume of human food that would render one liable is the size of a dried fig; this could be made up of several different foods items as long as the total volume of edible food is the size of a dried fig. Shells, seeds, stems, chaff and bran are not included in reaching this volume.