Strong’s Hebrew
H2141 — zakak
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
זָכַךְ
zakak — pronounced zaw-kak
a primitive root (compare 2135); to be transparent or clean (phys. or morally):--be (make) clean, be pure(-r). see H02135
4 occurrences in the KJV.
Job 9:30
If I wash myself with snow water, and make my hands never so clean;
Job 15:15
Behold, he putteth no trust in his saints; yea, the heavens are not clean in his sight.
Job 25:5
Behold even to the moon, and it shineth not; yea, the stars are not pure in his sight.
Lamentations 4:7
Her Nazarites were purer than snow, they were whiter than milk, they were more ruddy in body than rubies, their polishing was of sapphire:
