Visuddhimagga XV-31

Sattarasa dhātuyo dhammadhātuekadeso ca saṅkhatadhātu,

十七界及法界的一部分是「有为界」。

Ñ(XV,31): Seventeen elements and one part of the mental-data element are the formed element;

asaṅkhatā pana dhātu dhammadhātuekadesova.

「无为界」则只是法界的另一部分。

Ñ: but the unformed element is one part of the mental-data element only.

Anekadhātunānādhātuloko pana aṭṭhārasa dhātuppabhedamattamevāti. Iti sabhāvato vijjamānānaṃ sabbadhātūnaṃ tadantogadhattā aṭṭhāraseva vuttāti.

如是存在的一切界，从自性上说，都得含摄于十八界之内，所以只说十八界；

Ñ: The 'world of many elements, of various elements' is merely what is divided up into the eighteen elements. So they are given as eighteen because, as to individual essence, all existing elements are included in that [classification].