Dhammapada · 18.19

Paravajjānupassissa, niccaṃ ujjhānasaññino;Āsavā tassa vaḍḍhanti, ārā so āsavakkhayā.

Paravajjanupassissa, niccam ujjhanasannino; Asava tassa vaddhanti, ara so asavakkhaya.

For one who constantly contemplates others' faults — ever fault-finding — his own outflows grow; he is far from the destruction of outflows.

— Dhammapada 18.19

Source: Pali text from the Khuddaka Nikāya of the Pali Canon (oldest extant Buddhist scripture, compiled c. 3rd century BCE). Public-domain English readings drawn from F. Max Müller's translation in Sacred Books of the East, Vol X (1881) and the Buddhist Publication Society's freely-licensed Acharya Buddharakkhita rendering.