俱舍論頌疏論本 25.51

25.51

釋曰：初句答第一問，下三句答第二問。經說通行總有四種：一苦遲通行、二苦速通行、三樂遲通行、四樂速通行。道依四根本靜慮，名樂通行，以攝受支（十八禪支也）止觀均平，任運轉故，名之為樂，非樂受也。若依無色、未至、中間，名苦通行，以不攝支，止觀不等，艱辛轉故，名之為苦，非苦受也。謂無色界止多觀少，未至、中間觀多止少，名不等也。頌言所餘地者，即此無色等也然此樂、苦二通行中，鈍根名遲，行稽遲故；利根名速，通境疾故。

Explanation: The first line answers the first question; the lower three lines answer the second question. The sūtra speaks of four modes of progress in total: 1. difficult progress with slow comprehension; 2. difficult progress with rapid comprehension; 3. easy progress with slow comprehension; 4. easy progress with rapid comprehension. When the path relies on the four fundamental dhyānas, it is called easy progress: because it gathers factors (the eighteen dhyāna factors) and serenity and insight are balanced, proceeding spontaneously, it is called easy, not because it is pleasant sensation. If it relies on the formless [absorptions], the preparatory [stage], and the intermediate [dhyāna], it is called difficult progress: because it does not gather factors and serenity and insight are not equal, proceeding with hardship, it is called difficult, not because it is painful sensation. That is, in the formless realm there is much serenity and little insight; in the preparatory and intermediate [stages] there is much insight and little serenity; this is called unequal. When the verse says 'the remaining stages', it refers to these formless stages and so forth. However, within these two modes of easy and difficult progress, dull faculties are called 'slow' because their practice is tardy; sharp faculties are called 'rapid' because they penetrate the objective realm swiftly.