瑜伽師地論略纂 5.47

5.47

無間入等至中，漏、無漏純、雜三種，皆有四類。一、純有漏；二、純無漏；三、有無漏雜。　四類者：一、順入；二、逆入；三、順逆入；四、逆順入。此中但有初二。

In uninterrupted entry into meditative absorption, the three kinds—pure contaminated, pure uncontaminated, and mixed—each have four varieties: first, purely contaminated; second, purely uncontaminated; third, mixed contaminated and uncontaminated. / The four varieties are: first, direct entry; second, reverse entry; third, direct-then-reverse entry; fourth, reverse-then-direct entry. Here, only the first two are present.