大乘起信論裂網疏 4.6

4.6

衣服非臭非香，喻隨緣不變之性，本自非染非淨也。以臭物熏則有臭氣，喻不變之性隨於染緣，有染相也；以香物熏則有香氣，喻不變之性隨於淨緣，有淨用也。

The clothing being neither foul nor fragrant illustrates the nature that accords with conditions yet is immutable, originally being neither defiled nor pure. Being perfumed by a foul thing so that it has a foul scent illustrates the immutable nature according with defiled conditions to have defiled marks; being perfumed by a fragrant thing so that it has a fragrant scent illustrates the immutable nature according with pure conditions to have pure functions.