nirvana is samsara
(9) He who wishes to put on the yellow dress without having cleansed himself from sin, who disregards temperance and truth, is unworthy of the yellow dress.
(10) But he who has cleansed himself from sin, is well grounded in all virtues, and regards also temperance and truth, he is indeed worthy of the yellow dress.
I'm not sure about the translation using the word "sin." Unskillful action might be a better term.
"American Zen (monk and) author Brad Warner states that in Buddhism there is no concept of sin at all. The Buddha Dharma Education Association also expressly states "The idea of sin or original sin has no place in Buddhism." Zen student and author Barbara O'Brien has said that "Buddhism has no concept of sin." Walpola Rahula also disagreed with the notion of sin, saying "In fact there is no 'sin' in Buddhism, as sin is understood in some religions."
- Buddhist views on sin - Wikipedia