法華玄論 9.17

9.17

答：實如所問。但多寶即以此事為願，故開本迹也。又所以明多寶願者，以塔現故，寄古佛以明法身常；以本願故，集化身以顯本一。以事約而理周，蓋是至人之善巧也。又示多寶因果願行皆悉益物，明塔現謂果益物，舉本願謂因利緣。又涌塔讚嘆謂行益物，稱於本願謂願利緣。又多寶塔涌現則古佛降莚，以本願故化身雲集，時會奉覩則起奇特心，尊敬《法華》廣植諸善，有斯大益故稱本願也。

Answer: It is indeed as you ask. However, Prabhūtaratna made this very matter his vow, and therefore it opens the root and traces. Furthermore, the reason Prabhūtaratna's vow is clarified is that because of the stūpa's appearance, he used an ancient buddha to clarify that the dharmakāya is eternal; because of the original vow, he gathered the transformation bodies to reveal that the root is one. Expressing profound principle with concise events is indeed the skillful means of the consummate person. Moreover, it shows that Prabhūtaratna's causes, fruits, vows, and practices all benefit beings: clarifying the appearance of the stūpa refers to benefiting beings through the fruit; citing the original vow refers to aiding conditions through the cause. Furthermore, the welling forth of the stūpa and praising refers to benefiting beings through practice; matching the original vow refers to aiding conditions through vows. In addition, when Prabhūtaratna's stūpa welled forth, an ancient buddha descended upon the assembly; because of the original vow, transformation bodies gathered like clouds, and when the assembly beheld them, they gave rise to a sense of wonder, revered the Lotus Sūtra, and broadly planted roots of goodness. Having such great benefit, it therefore matched his original vow.