ماجهيما نيكايا 5:12
SUJATOAnekapariyāyenāvuso ariṭṭha, antarāyikā dhammā antarāyikā vuttā bhagavatā, alañca pana te paṭisevato antarāyāya.
In many ways the Buddha has said that obstructive acts are obstructive, and that they really do obstruct the one who performs them.