四分律比丘含注戒本 1.3

1.3

《四分戒本》者，蓋開萬行之通衢，引三乘之正軌也。自法王利見，弘濟在緣，程上聖之悽惶，悼小凡之沈溺。故能闢不諱之門，示祕密之深術；張無問之說，顯初學之津塗。遂靜處而興教源，集眾而宣玄範。前明由序，廣陳發致之功；後列大宗，盛羅機欲所被。約時敷演，通行於是承遵；合潔等聞，正法由茲久住。

The Prātimokṣa of the Four-Part [Vinaya] opens the thoroughfare for the myriad practices and guides along the true course of the Three Vehicles. Ever since the King of Dharma appeared auspiciously, his vast salvation depended on conditions; he gauged the anxieties of superior sages and grieved over the sinking of petty worldlings. Thus he was able to open the unreserved gate and reveal the profound techniques of secrets, unfolding teachings given unasked and displaying the ford for beginners. Consequently, he gave rise to the source of the teaching in tranquil places and assembled the multitude to proclaim the profound standard. First, he clarified the preface, setting forth at length the merit of generating aspiration; next, he laid out the great principles, abundantly organizing what would encompass the capacities and inclinations [of beings]. Expounding them in accordance with the times, common practice was thereby upheld; harmonizing and purifying what was equally heard, the True Dharma was by this means made to abide long.