Majjhima Nikaya 4:63
SUJATOSo ‘idaṁ dukkhan’ti yoniso manasi karoti, ‘ayaṁ dukkhasamudayo’ti yoniso manasi karoti, ‘ayaṁ dukkhanirodho’ti yoniso manasi karoti, ‘ayaṁ dukkhanirodhagāminī paṭipadā’ti yoniso manasi karoti.
They rationally apply the mind: ‘This is suffering’ … ‘This is the origin of suffering’ … ‘This is the cessation of suffering’ … ‘This is the practice that leads to the cessation of suffering’.