法華玄論 9.104

9.104

答：已如前說。窮子所見著弊垢衣，正就隱本垂迹，故偏就二佛異義論之。若是一佛，則失斯意也。

Answer: It has already been explained as above. What the impoverished son saw was [the elder] dressed in worn and dirty clothing; this refers precisely to concealing the original and projecting the trace, and therefore it is discussed exclusively in terms of the aspect of difference between the two Buddhas. If it were one Buddha, then this meaning would be lost.