The Laṅk�vat�ra Sūtra
Then at that time the Blessed One recited this couplet of verses:
I always preach emptiness which is beyond eternalism and nihilism; Samsara is like a dream and a vision, and karma vanishes not.
Space, Nirvana, and the two forms of cessation— thus the ignorant discriminate the things which are not effect-producing, but the wise stand above being and non-being.
At that time again, the Blessed One said this to Mah�mati the Bodhisattva-Mah�sattva; This [teaching of] emptiness, no-birth, non-duality, and no-self-nature is found in all the sutras of all the Buddhas, and this doctrine is recognised in every one of them. However. Mah�mati, the sutras are the teaching in conformity with the dispositions of all beings and deviate from the [real] sense, and not the truth-preserving statement. Mah�mati, it is like unto the mirage which entices the deer with its treacherous springs, the springs are not there but the deer are attached, imagining them to be real. So with the teachings disclosed in all the sutras, they are for all beings for the gratification of their own discriminating minds. They are not the truth-preserving statements meant for noble wisdom to grasp. For this reason, Mah�mati, be in conformity with the sense and be not engrossed in the word-teaching.