妙法蓮華經玄贊 2.252

2.252

The commentary says: This explains their royal governance. In no single world are there two wheel-turning kings; how can it now be said that each ruled over the four continents? It is now explained that the eight sons ruled in succession, not at the same time. However, to harmonize this through meaning: in a decreasing kalpa a buddha arises, while in an increasing kalpa a wheel-turning king appears; how could that buddha have sons who became wheel-turning kings? These were ones who should have succeeded as wheel-turning emperors ruling the four continents, just as Śākyamuni Buddha should have been a golden wheel-turning king, not that they had actually already received it, because the kalpa was gradually decreasing; for this reason, only when it increases to eighty thousand years will Śaṅkha appear. At the beginning of the decrease of the tenth kalpa, Maitreya will appear; because the wheel-turning king has a long life, he will see Maitreya. Or, this reward buddha differs from an emanation buddha: a reward buddha does not necessarily appear in a decreasing kalpa, so it is possible for him to have sons who became wheel-turning kings. Varaprabha converted the eight sons so that they became firm in bodhi and attained entry into the eighth ground; thus we know that a reward buddha also first expounds the Anantanirdeśa for bodhisattvas and afterwards expounds the Lotus Sūtra for śrāvakas, just as in the Drum Sound King Sūtra, Amitābha Buddha has a wife and children.