四分律行事鈔資持記 2.107

2.107

次《涅槃》中，初引經。忉利天，即三十三天；日月歲數，亦約人間計之。與下，通會。俗中算數，十十為百，十百為千，十千為萬，十萬為億，十億為兆（此為小數）；或以百百為千，千千為萬，萬萬為億等（此為大數）。前經據其大數，《涅槃》從小數；然二經對天不同，九百八百之異，未可和會。

Next, regarding the Nirvāṇa [Sūtra], it first quotes the sūtra. The Trāyastriṃśa Heaven is the Heaven of the Thirty-Three; its counts of days, months, and years are also calculated in terms of the human world. From "and..." onward, it reconciles them. In secular arithmetic, ten tens are a hundred, ten hundreds are a thousand, ten thousands are a myriad, ten myriads are an yi, ten yi are a zhao (this is the minor numbering system); or, a hundred hundreds are a thousand, a thousand thousands are a myriad, a myriad myriads are an yi, and so forth (this is the major numbering system). The previous sūtra relies on its major numbering system, while the Nirvāṇa [Sūtra] follows the minor numbering system; however, the two sūtras correlate with heavens differently, and with the discrepancy between nine hundred and eight hundred, they cannot yet be harmonized.