一尘不染

untainted by even a speck of dust (idiom); selfless and incorruptible / spotless

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

dust / dirt / earth

no; not so / (bound form) not; un-

to dye / to catch (a disease) / to acquire (bad habits etc) / to contaminate / to add color washes to a painting