chasak (Hebrew #2820)
to restrain or (reflex.) refrain; by implication, to refuse, spare, preserve; also (by interch. with 2821) to observe
KJV usage: assuage, X darken, forbear, hinder, hold back, keep (back), punish, refrain, reserve, spare, withhold.
Pronounce: khaw-sak'
Origin: a primitive root
chashak (Hebrew #2821)
to be dark (as withholding light); transitively, to darken
KJV usage: be black, be (make) dark, darken, cause darkness, be dim, hide.
Pronounce: khaw-shak'
Origin: a primitive root