廣弘明集 9.129

9.129

真人內朝律云真人曰。凡男女至朔望日。先齋三日入私房。詣師所立功德。陰陽並進日夜六時。此諸猥雜不可聞說。又道律云。行氣以次。不得任意。排醜近好抄截越次。又玄子曰。不鬲戾得度世。不嫉姤世。可度陰陽合乘龍去云云。

The Zhenren neichao lü states: ‘The Perfected said: Whenever men and women reach the new and full moons, they must first fast for three days, then enter a private chamber and go to the master's place to establish merit. Yang and yin advance together throughout the six periods of the day and night.’ These vile and promiscuous matters are unfit to be heard or spoken of. Furthermore, the Daoist Vinaya says: ‘Circulate qi in proper order; one must not follow personal inclinations, casting aside the ugly to draw near the attractive, or cutting across and violating the sequence.’ The Xuanzi also states: ‘Without stubborn perversity, one attains deliverance from the world; without jealousy, one can be saved. When yin and yang unite, one mounts dragons and ascends,’ and so forth.