注大乘入楞伽經 5.26

5.26

"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.