In a famous old story, Shenxiu wrote that, in our practice, we must constantly clean and polish the body-mind to keep all free of dust. To that, Huineng responded that there's never a place for dust to gather ...
Thus, Master Dogen wrote in the Fukanzazengi:
Furthermore, the whole body far transcends dust and dirt: who could believe in the means of sweeping and polishing? [Nishijima]
Indeed, the whole body is free from dust. Who could believe in a means to brush it clean? [SZTP]
Actual mummy of Huineng (d. 713), 6th Chan/Zen Patriarch, prior to near destruction in Cultural Revolution