A primitive root (compare zakah); to be transparent or clean (phys. Or morally) -- be (make) clean, be pure(-r).
see HEBREW zakah
H2141. zakak
[זָכַךְ] verb be bright, clean, pure (kindred with foregoing. Only Lamentations, Job) —
Qal Perfect only 3 masculine plural זַכּ֫וּ; —
1 be right, shining, figurative of splendour of nobles ׳ז מִשֶּׁלֶג נְזִירִים Lamentations 4:7 ("" צַחוּ מֵחָלָב).
2 be clean, pure in God's sight, of heavens Job 15:15, of stars 25:5 ("" יַאֲהִיל of moon; compare also יִזְכֶּה 15:14; 25:4).
Hiph`il cleanse, only Perfect1singular כַּמָּֽי׃ בְּבֹר וַהֲזִכּוֺתִי Job 9:30, figurative of making morally spotless ("" הִתְרָחַצְתִּי).