Dhammapada · 7.4

Yassāsavā parikkhīṇā, āhāre ca anissito;Suññato animitto ca, vimokkho yassa gocaro;Ākāseva sakuntānaṃ, padaṃ tassa durannayaṃ.

Yassasava parikkhina, ahare ca anissito; Sunnato animitto ca, vimokkho yassa gocaro; Akaseva sakuntanam, padam tassa durannayam.

One whose taints are destroyed, who clings not to food, whose domain is emptiness and signlessness — even his footprint, like birds in the sky, is hard to trace.

— Dhammapada 7.4

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.