廣弘明集 13.97

13.97

外論曰。夫老君道契環中與虛空而等量。神超象外隨變化而無窮。所以壽命固不同凡。隱顯居然異俗。

The external treatise says: Lord Lao’s Way accords with the center of the ring, possessing a measure equal to empty space; his spirit transcends beyond appearances, adapting to transformations without end. Therefore, his lifespan is certainly not like that of ordinary mortals, and his hiddenness or manifestation is distinctly different from the worldly.