Bhaddekarattasutta 8.7

8.7

viññāṇaṃ attato samanupassati, viññāṇavantaṃ vā attānaṃ attani vā viññāṇaṃ, viññāṇasmiṃ vā attānaṃ—

consciousness as self, self as having consciousness, consciousness in self, or self in consciousness.