Mundaka Upanishad : 3 -2- 1 :
brahma veda brahma Eva bhavati :
He who knows the brahman becomes the brahman.
This s’ankarAcArya tells us is the param prAptavya sthAnam, param ayanam, parAyaNam, the ultimate state to reach.
When dharmarAja asks Bhishma, lOkE kim va api ekam parAyaNam, he is asking him, what is that perfect state in this world?
And Sankaracharya is telling is – that is the state of knowing the brahman, since to know the brahman is to be the brahman.
- Adi Sankara’s commentary on Vishnu Sahasranama.