俱舍論頌疏論本 14.108

14.108

釋曰：此有三意制欲邪行：一、最可呵責，侵他妻故，感惡趣故，非非梵行。二、易遠離故，謂邪行易遠離，在家耽欲，離非梵行難故，不制離非梵行也。三、得不作故，謂諸聖者於欲邪行決定不作，得不作律儀。經生聖者，性戒成就，雖易多生，亦不犯故。離非梵行則不如是，謂初二聖有自妻故，有非梵行。由上三因，是故近事制欲邪行。若不爾者，應經生聖犯近事戒，有自妻故。

The explanation says: There are three reasons for prohibiting sexual misconduct: First, it is the most blameworthy, because it violates another's wife and brings about rebirth in bad destinies, whereas unchaste conduct [itself] does not necessarily do so. Second, it is easy to abandon: that is, misconduct is easy to abandon, whereas for householders indulged in sensual pleasures, abstaining from all unchaste conduct is difficult; therefore, abstaining from unchaste conduct was not instituted. Third, [the noble ones] have obtained its non-performance: that is, the noble ones definitely do not engage in sexual misconduct, having obtained the discipline of non-performance; a noble one passing through subsequent births is perfected in natural morality, and even though transitioning through many births, will never violate it. Abstaining from unchaste conduct is not like this: the noble ones of the first two fruits have their own wives, and therefore engage in unchaste conduct. Due to the above three reasons, sexual misconduct is prohibited for lay followers. Were it not so, a noble one passing through subsequent births would violate the precepts of a lay follower, because they have their own wives.