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]