Where in the Vimalakīrti Sutra is this stated?

I was reading some of the writings of Nichiren Daishōnin, and I came across this part where he says that it states in the Vimalakīrti Sutra that, "if the minds of living beings are impure, their land is also impure, but if their minds are pure, so is their land. There are not two lands, pure or impure in themselves. The difference lies solely in the good or evil of our minds" (On Attaining Buddhahood in this Lifetime 4). I assume that he was paraphrasing, but I couldn't find any footnotes about were he got this from. I've never read the Vimalakīrti Sutra, but if there is a passage where this message could have been taken from, I'd be happy to see it. Thank you!