瑜伽論記 4.306

4.306

此意答言：謂不相違。十六行中先無常者，則據見道已前初修加行先觀無常，無常故苦苦故無我，無我故空，從易至難作此次第，此中則據初入見道觀真如時空無人法故先說空，從真見道入相見道，次起無願、無常、苦觀，方得清淨。

The intended response says: They are not contradictory. That impermanence comes first among the sixteen aspects is based on initial preparatory training before the path of seeing, where one first contemplates impermanence; because of impermanence, there is suffering; because of suffering, there is non-self; because of non-self, there is emptiness—making this sequence from easy to difficult. Here, it is based on initial entry into the path of seeing, when one contemplates tathatā as empty of persons and dharmas, and therefore emptiness is spoken of first; entering the path of seeing with signs from the true path of seeing, one next gives rise to the contemplation of wishlessness, impermanence, and suffering, and only then attains purification.