Dutiyasoceyyasutta 3.6

3.6

santaṃ vā ajjhattaṃ vicikicchaṃ: ‘atthi me ajjhattaṃ vicikicchā’ti pajānāti; asantaṃ vā ajjhattaṃ vicikicchaṃ: ‘natthi me ajjhattaṃ vicikicchā’ti pajānāti; yathā ca anuppannāya vicikicchāya uppādo hoti, tañca pajānāti; yathā ca uppannāya vicikicchāya pahānaṃ hoti, tañca pajānāti; yathā ca pahīnāya vicikicchāya āyatiṃ anuppādo hoti, tañca pajānāti.

When they have doubt in them they understand ‘I have doubt in me’; and when they don’t have doubt in them they understand ‘I don’t have doubt in me’. They understand how doubt arises; how, when it’s already arisen, it’s given up; and how, once it’s given up, it doesn’t arise again in the future.