起信論疏筆削記 5.26

5.26

疏　以前下，二、通疑也。或曰：「前之三根各攝論文一段，何以信心初位獨用四文？」故此通之。前位漸深，望於初位，故名根勝。信根欲成，縱遇惡緣，亦少退屈，故云難退。然亦未必一向不退，故云難也。如鶖子入住，猶自退轉，況十信耶？根劣者，謂始自異生，初登信位，善根微薄，不異輕毛，遭善難進，遇惡易退，故假多方以助道力，由是具四也。

Commentary: "From the preceding..." Second, resolving doubts. Someone might ask: "The preceding three faculties each encompass a single section of the treatise text; why does the initial stage of faith alone employ four texts?" Hence this resolves it. The preceding stages are gradually deeper; viewed relative to the initial stage, their faculties are named superior. When the root of faith is about to be perfected, even if they encounter adverse conditions, there is little retrogression; hence it is called "difficult to retrogress." However, it is not necessarily entirely without retrogression; hence it is called "difficult." Just as Śāriputra, having entered the abodes, still retrogressed, how much more so for the ten faiths? "Inferior faculties" refers to those who, having just emerged from ordinary beings and first mounted the stage of faith, have thin and feeble roots of goodness, no different from light down; encountering goodness it is difficult to advance, and encountering evil it is easy to retrogress. Therefore, they rely on many methods to assist the power of the path; because of this, all four are present.