法華玄論 1.92

1.92

答：《中論》云「雖復懃精進，修行菩提道，若先非佛性，云何得成佛？」長行釋云「如鐵無金性，雖復鍛鍊，終不成金。」若《法華》未辨佛性，但緣用成佛義者，既無佛性則無成佛理，亦如〈師子吼品〉廣難無性成佛義，以理推之必明佛性。

Answer: The Mūlamadhyamakakārikā states: 'Although one diligently exerts effort and practices the path to bodhi, if one were originally not of buddha-nature, how could one attain buddhahood?' The prose commentary explains: 'Just as iron lacks the nature of gold, though one smelts it, it never becomes gold.' If the Lotus Sūtra had not yet distinguished the buddha-nature, and only held the doctrine that one attains buddhahood by conditioning causes, then since there would be no buddha-nature, there would be no principle of attaining buddhahood; this is also just as the 'Lion's Roar Chapter' extensively challenges the doctrine of attaining buddhahood without nature. Deducing it through principle, it must clarify the buddha-nature.