Who is the Supremely Venerable One?

The living beings, ever tormented by pain,
Blind and without a guide,
Do not recognize the Path wherein pain is terminated,
Nor do they know enough to seek deliverance.
Throughout the long night of time they gain in evil destinies
And reduce the ranks of the gods.
From darkness proceeding to darkness,
They never hear the Buddha’s name.
Now that the Buddha has gained the supremely
Serene Dharma free of outflows,
We and the gods and men,
In order to gain the greatest advantage,
For this purpose, all bowing our heads,
Submit to the Supremely Venerable One. (LS, Chapter 7, pp. 133-134)