The additional passages are from the seventh century Cittavisuddhiprakarana, of Aryadeva, cited in W. T. de Bary, The Buddhist Tradition, Vintage Books, 1972.
Identity of the world (samsara) and nirvana.
Mind is the origin of all things.
Mind is the universal seed,
Both samsara and nirvana spring forth from it. [41.]
As is nirvana, so is samsara.
Do not think there is any distinction.
Yet it possesses no single nature
For I know it as quite pure. 
Here there is no beginning, no middle, no end,
Neither samsara nor nirvana.
In this state of highest bliss
There is neither self nor other. 
Whatever you see, that is it,
In front, behind, in all the ten directions. 
One should not think of molecules or atoms;
It is this supreme bliss that pours forth unceasingly as existence. 
Do not sit at home, do not go to the forest,
But recognize mind wherever you are.
When one abides in complete and perfect enlightenment,
When samsara and where is nirvana?