大乘百法明門論開宗義決 1.175

1.175

生在下地未離下染等者。下上地惑麁細懸殊。下惑未斷上惑不起。要伏下惑上惑現前。此總說已別分別者。如初靜慮名為下地。修第二定未得根本退生自地。是故名為生在下地。未能捨離初靜慮惑。第二靜慮煩惱不生。若得二地根本定者。伏初靜慮下地煩惱。第二靜慮上惑現起。於二靜慮下上既然。三四靜慮四無色定。伏下起上當知亦爾。

As for "being born in a lower stage without having abandoned lower defilement, etc.": the defilements of the lower and higher stages are vastly disparate in terms of coarseness and subtlety; if the lower defilements have not been severed, the higher defilements do not arise; one must suppress the lower defilements before the higher defilements become manifest. Having explained this generally, to distinguish it specifically: for example, the first dhyāna is called a lower stage; if one cultivates the second dhyāna without yet attaining its fundamental state and degenerates, being born in one's own stage, this is called being born in a lower stage. When one has not been able to abandon the defilements of the first dhyāna, the afflictions of the second dhyāna do not arise. If one attains the fundamental concentration of the second stage, suppressing the lower-stage afflictions of the first dhyāna, the higher defilements of the second dhyāna will arise and manifest. As this is true between the lower and higher of these two dhyānas, one should know that it is also likewise for the third and fourth dhyānas and the four formless concentrations: suppressing the lower and giving rise to the higher.