Rashi

Wash, cleanse yourselves Voweled with a ‘patach,’ the imperative form, since it is derived from רְחַץ, but רָחֲצוּ, [in the past tense, is voweled with a ‘kamatz’ because it is derived from רָחַץ]. Wash, cleanse yourselves, remove, learn, seek, strengthen, perform justice, plead, go Ten exhortations of the expression of repentance are [listed] here, corresponding to the Ten Days of Penitence and to the ten verses of Kingship, Remembrances, and Shofaroth [in the musaf service of Rosh Hashanah]. cease to do evil Desist from your evil deeds. to do evil Heb. הרע, like לְהָרֵעַ, to do evil. [Rashi explains this because the preposition is absent in Hebrew.] Scripture does not have to write מֵהָרֵעַ, desist from doing evil, for so does the Biblical language treat the expression of חֲדָלָה, stopping, [e.g.,] “and he failed to make (לַעֲשׂוֹת) the Pesach” (Num. 9:13); “until he stopped counting (לִסְפֹּר)” (Gen. 41:49). That is to say, the counting stopped, the making failed, here too, stop the evildoing.