… “he should dwell contemplating nonself in form … as above … he is freed from suffering, I say.”
SN22.42: Catutthaanudhammasutta
Catutthaanudhammasutta: In Accordance with the Dhamma (4) - translated by Bhikkhu Bodhi
Translations:Thanissaro Bhikkhu
Translated by Bhikkhu Bodhi. Source text via SuttaCentral.