Anattalakkhaṇasutta

sn22.59:5.1 Consciousness is not-self.

sn22.59:5.2 For if consciousness were self, it wouldn’t lead to affliction. And you could compel consciousness:

sn22.59:5.3 ‘May my consciousness be like this! May it not be like that!’

sn22.59:5.4 But because consciousness is not-self, it leads to affliction. And you can’t compel consciousness:

sn22.59:5.5 ‘May my consciousness be like this! May it not be like that!’