Srimad-Bhagavatam: Canto 7 - Chapter 1 - Verse 62
भावाद्वैतं क्रियाद्वैतं द्रव्याद्वैतं तथात्मन: ।वर्तयन्स्वानुभूत्येह त्रीन्स्वप्नान्धुनुते मुनि: ॥ ६२ ॥
bhāvādvaitaṁ kriyādvaitaṁdravyādvaitaṁ tathātmanaḥvartayan svānubhūtyehatrīn svapnān dhunute muniḥ
After considering the oneness of existence, activity and paraphernalia and after realizing the self to be different from all actions and reactions, the mental speculator [muni], according to his own realization, gives up the three states of wakefulness, dreaming and sleep.
The three words bhāvādvaita, kriyādvaita and dravyādvaita are explained in the following verses. However, one has to give up all the nonduality of philosophical life in the material world and come to the actual life of reality in the spiritual world in order to attain perfection.