Midrash on Job 9:30: Bereshit Rabbah & Classical Sources

אִם־הִתְרָחַ֥צְתִּי במו־[בְמֵי־] שָׁ֑לֶג וַ֝הֲזִכּ֗וֹתִי בְּבֹ֣ר כַּפָּֽי׃

If I wash myself with snow water, And make my hands never so clean;