瑜伽論記 2.31

2.31

辨色界處中，凡論修禪有三：一、唯有漏熏下四定，二、唯無漏八地以上變易生死，三、有漏無漏，如五淨居業雖凡位而造，由今無漏資有漏定，更助故業令勝上生。

In distinguishing the locations of the form realm, cultivating dhyāna is generally discussed in three ways: first, purely contaminated [dhyāna] perfuming the lower four dhyānas; second, purely uncontaminated [dhyāna] for the transformationally born birth-and-death of the eighth stage and above; third, contaminated and uncontaminated, like the karma of the five pure abodes: although created in an ordinary state, because uncontaminated [dhyāna] now assists the contaminated dhyāna, it further aids the past karma to cause a superior rebirth.