注大乘入楞伽經 5.26

5.26

七反生者，謂欲界一地，九品俱生煩惱，共潤七生也。初品潤二生，次三品各潤一生，次二品共潤一生，後三品共潤一生。明須陀洹極鈍者，未斷欲界惑，故人天七反得阿羅漢。喻如毒蛇噬人，七步即死。何以不四六？為大力故。何以不八？為毒力故。以譬須陀洹何以不六生？煩惱力強故。何以不八生？無漏業成熟故。中機者，或三生五生，得阿羅漢涅槃果。上機者，即此一生，得阿羅漢果，名現滅須陀洹，不說中間經於二果。

"Reborn seven times" means that the nine grades of innate defilements of the single ground of the desire realm together moisten seven rebirths. The first grade moistens two rebirths, the next three grades each moisten one rebirth, the next two grades together moisten one rebirth, and the last three grades together moisten one rebirth. This clarifies that the extremely dull srotāpanna has not yet severed the defilements of the desire realm, so through seven returns among humans and devas they attain the arhat [fruit]. It is like a venomous snake biting a person: after seven steps, they die. Why not four or six? Because of its great power. Why not eight? Because of the power of the poison. By analogy, why is the srotāpanna not reborn six times? Because the power of defilements is strong. Why not eight rebirths? Because untainted karma has matured. Those of middling capacity attain the arhat fruit of nirvāṇa in three or five rebirths. Those of superior capacity attain the arhat fruit right in this one life, termed the srotāpanna who enters cessation in the present; it is not said that they pass through the intermediate two fruits.