SN 22.49 Soṇa Sutta: Conceit
The Buddha talks to someone called Soṇa saying:
Soṇa, when any ascetics or brahmins on the basis of form, feeling, perception, volitional formations or consciousness, which is impermanent, suffering and subject to change, regard themselves thus ‘I am superior’ or ‘I am equal’ or ‘I am inferior’ what is that due to apart from not seeing things as they really are?
What do you think Soṇa, is [form, feeling, perception, volitional formations, consciousness] permanent or impermanent? ‘Impermanent, venerable Sir!’
Is what is impermanent suffering or happiness? ‘Suffering, venerable Sir!’
Is what is impermanent, suffering and subject to change fit to be regarded thus: ‘This is mine. This I am. This is my self?’ ‘No, venerable Sir!’
Therefore Soṇa, any kind of [5 skandhas] whatsoever, whether past, future or present, internal or external, gross or subtle, inferior or superior, far or near, all should be seen as it really is with correct wisdom thus ‘This is not mine, this I am not, this is not myself’