梵網經古迹記 2.174

2.174

述曰：此謗三寶，第十重攝。詐覓利邊，并得此罪。媒嫁令婬，第三重攝。然就媒邊，結此罪耳。其殺生等，隨應亦爾。不敬齋邊，制為輕罪。言「六齋」者，黑白各三，謂第八日、十四、十五。此日鬼神得勢傷人，為令免害，故須制也。「年三長齋」者，《提謂經》云：正月本齋十五日，五月本齋十五日，九月本齋十五日。三齋因緣，如經廣說。

The commentary states: Slandering the Three Jewels is subsumed under the tenth major precept; in terms of deceitfully pursuing profit, one also incurs this offense. Matchmaking to bring about sexual misconduct is subsumed under the third major precept; however, in terms of acting as a matchmaker, one incurs this offense. Killing living beings and so forth are likewise according to the case. In terms of disrespecting the fasts, it is instituted as a minor offense. Regarding 'the six fast days', there are three each in the dark and bright halves of the month, namely the eighth, fourteenth, and fifteenth days; on these days ghosts and spirits gain power to harm people, and to enable people to escape harm, this was instituted. Regarding 'the three long fasts of the year', the Tiwei Sūtra says: 'The original fast of the first month lasts fifteen days, the original fast of the fifth month lasts fifteen days, and the original fast of the ninth month lasts fifteen days.' The causes and conditions of the three fasts are explained at length in the sūtra.