梵網經菩薩戒本疏 3.4

3.4

First, regarding the intention behind the proscription, there are briefly ten meanings: First, because the karmic path is heavy. If it is illicit, it is subsumed under the ten unwholesome karmas; bearing this heavy offense, one is incapable of entering the path, and so it must be proscribed. Second, because the bondage is deep. Within the prison of saṃsāra, lust is the cangue and lock. The Dazhidulun says: "Although the mind of sexual desire does not torment sentient beings, because it binds the mind, it is a great offense." Third, because it is the root of saṃsāra. Driven by greedy attachment to sexual indulgence, one drifts in the transmigration of saṃsāra; in the ocean of desire and the river of lust, one drowns without shore. Fourth, because it ruins wholesome qualities. The Mahāsāṃghika Vinaya states: "Nothing is more terrifying than women. There is nothing through which righteousness is ruined and virtue destroyed that does not stem from them." Looking with a defiled mind is a transgression of the vinaya. If it is so even for the Hīnayāna, how much more so for the bodhisattvas and others. The Bodhisattvabhūmi states that a bodhisattva fears saṃsāra hundreds of thousands of millions of times more than a śrāvaka. Fifth, because it ruins the world. The Saddharmasmṛtyupasthāna Sūtra states: "The suffering obtained by men in the world is all due to wives and women; whether young or middle-aged, all stems from this cause. Women ruin the world, causing all good to be utterly destroyed. Among the devas, there is no greater bondage than female form. Women bind the devas and lead them to the three evil destinies." Sixth, because it disturbs the calm mind. The fire of desire agitates the mind, causing one to lose dhyāna and lose mindfulness. The waves of the ocean of desire shatter the water of samādhi. Seventh, because one enters the net of Māra. Licking the honey on a blade's edge and coveting the color of a poisonous flower harms sentient beings, which is Māra's wish. A sūtra states: "These five desires are the realm of the Māras." Eighth, because one loses supernatural powers. Just as an ṛṣi saw a woman, gave rise to defilement, and lost his powers and fell; or just as the unicorn ṛṣi soared through the air among the cliff peaks, and was later ridden on the neck by a courtesan and brought into the human world. Ninth, because it obstructs nirvāṇa. Hence in the vinaya, sexual misconduct is the first precept; if a monk violates this, he cannot attain nirvāṇa in this life. Tenth, because it obstructs bodhi. Hence a sūtra states: "The five desires are dharmas that obstruct the path; they can obstruct rebirth in heaven, how much more so the unsurpassed path!" Because of such limitless faults, it must be proscribed.