Английский Этимологический словарь - sack (1)

- "large bag," O.E. sacc (W.Saxon), sec (Mercian), sжc (Old Kentish) "large cloth bag," also "sackcloth," from L. saccus, from Gk. sakkos, from Semitic (cf. Heb. saq "sack"). The wide spread of the word (O.Fr. sac, O.N. sekkr, etc.) is probably due to the story of Joseph. Slang meaning "bunk, bed" is from 1825. The penitential sackcloth (M.E.) of the Bible was of goats' or camels' hair, the coarsest possible clothing. The meaning "dismiss from work" is 1825, perhaps from the notion of the worker going off with his tools in a bag (original formula was to give (someone) the sack).