"The Twenty-Five Sages' Dharma Gates of Perfect Penetration in Volume 5 of the Shurangama Sutra: Mahāmaudgalyāyana"

Mahāmaudgalyāyana then rose from his seat, prostrated at the Buddha's feet, and addressed the Buddha, saying: "When I first went out to seek alms on the road, I encountered Uruvilvā Kāśyapa, Gayā Kāśyapa, and Nadī Kāśyapa, the three Kāśyapa brothers, who were expounding the profound meaning of the Buddha's teaching on dependent origination. Upon hearing this, my mind was instantly awakened, and I attained great comprehension of the doctrine of dependent origination. The Tathāgata graciously bestowed upon me the attainment of the fourth fruition of Arhatship. Immediately, the kasaya robe draped itself over me, my hair and beard fell away, and the light of great wisdom radiated from my mind—like clarifying muddy water that, through sustained effort, gradually becomes pure and luminous. This was my foremost attainment."

Mahāmaudgalyāyana's self-described Dharma door of cultivation, or realization, was the simplest. Why was it so simple? Because he had cultivated it in past lives; his manas-root (seventh consciousness) had already attained realization countless times. In this present life, upon hearing the essential points of the Dharma, his new mental consciousness (sixth consciousness) attained realization almost instantly upon a brief moment of focused contemplation, without the need for the laborious process of perfuming the manas-root. His manas-root was inherently attuned to the fourth fruition of Arhatship from birth, possessing extremely high cultivation, freedom from afflictions, and profound wisdom—only the mental consciousness remained to be aligned. When a Stream-enterer (first fruition) returns to the human realm, since the manas-root attained realization in the past life but the new mental consciousness has not yet done so, the process of realization is faster than for an ordinary person. However, compared to Arhats, it is still slow. This is because the wisdom of non-self attained by the manas-root is still shallow, and fundamental ignorance remains heavy; thus, its perfuming influence on the mental consciousness is slight, leaving the mental consciousness burdened with ignorance. Therefore, upon re-encountering the Buddha Dharma, one still needs to practice for a period before re-attaining the fruition, though it is faster than for someone who has never attained it before. Facts demonstrate that in the process of cultivation and realization, not only is the learning of the mental consciousness important, but the perfuming and cultivation of the manas-root are even more crucial. In subsequent lives, the manas-root can perfume and guide the mental consciousness. Later, the mental consciousness, upon learning new and profound Dharma, can in turn perfume and guide the manas-root. When these two mutually perfume and guide each other, progress on the path advances very rapidly.