Proverbs 30:12

There is a generation who are pure in their own eyes and yet are not washed ¹  from their filthiness. ² 

Jud 17:5,13; 1Sa 15:13,14; Job 33:9; Ps 36:2; Ps 51:2,7; Pr 21:2; Isa 1:16; Isa 65:5; Jer 2:22-24,35; Jer 4:14; Eze 36:25; Zec 13:1; Lu 11:39,40; Lu 16:15; Lu 18:11; 1Co 6:11; 2Ti 3:5; Tit 1:15,16; Tit 3:5; 1Jo 1:7; 1Jo 1:8-10; Re 1:5

¹ tn The verb רָחַץ (rakhats) means “to wash; to wash off; to wash away; to bathe.” It is used of physical washing, ceremonial washings, and hence figuratively of removing sin and guilt through confession (e.g., Isa 1:16). Here the form is the Pual perfect (unless it is a rare old Qal passive, since there is no Piel and no apparent change of meaning from the Qal).

sn The point of the verse is that there are people who observe outer ritual and think they are pure (טָהוֹר [tahor] is the Levitical standard for entrance into the sanctuary), but who pay no attention to inner cleansing (e.g., Matt 23:27).

² sn Filthiness often refers to physical uncleanness, but here it refers to moral defilement. Zech 3:3-4 uses it metaphorically as well for the sin of the nation (e.g., Isa 36:12).