瑜伽師地論略纂 2.61

2.61

結云「內、外六處諸法，差別有六百六十」者，此據十二處，各增至十，一一皆有五十五種，此成六百六十所可應有增數之法。理實不然。五根增中，皆無增十，而有十一，已剩其五；意處至十二，而無增十，後剩十三。於此增數，合剩十八，況復不計法界所攝八十七法等。由此應知，但據十二處各增至十之總大數。

The concluding statement that "the differences in the dharmas of the six internal and six external āyatanas amount to six hundred and sixty" is based on the twelve āyatanas, each progressively enumerated up to ten, with each one having fifty-five varieties, which makes six hundred and sixty dharmas that ought to be progressively enumerated. In actual principle this is not so. In the progressive enumeration of the five faculties, none has a progression of ten, but has eleven, already exceeding by five; the mind āyatana goes up to twelve without a progression of ten, and the latter exceeds by thirteen. In this progressive enumeration, there is an excess of eighteen altogether, not to mention not calculating the eighty-seven dharmas subsumed by the dharma-dhātu, and so forth. From this one should know that it merely refers to the grand total of the twelve āyatanas each progressively enumerated up to ten.