妙法蓮華經文句 2.16

2.16

本者，本住大寂滅定，長壽是常，無病是樂，不夭是我，寂靜是淨；居此四德之本，迹示六根寂靜耳。

In terms of the origin: at the origin he abides in the concentration of great tranquil extinction: long life is permanence, freedom from illness is joy, freedom from untimely death is self, and stillness is purity. Residing at the origin of these four virtues, in traces he merely displays the stillness of the six sense faculties.