瑜伽論記 17.454

17.454

答初超難故從五入五從四入四，後成時易無發亦人如造金時，用多方便始乃能成如穬麥許，即自念言我造金畢，從是已後若化金山不多功力，此亦如是。

Answer: The initial leap is difficult, so one enters five from five and enters four from four; when accomplished later, it is easy and takes no effort. It is like when refining gold: using many expedients, one only then manages to produce an amount like a grain of barley, and immediately thinks to oneself, 'I have finished making gold.' From then on, even if one transforms a mountain of gold, it does not require much effort. This is also like that.