Samannaphalasutta 1.28

1.28

‘When, one day, I had thus asked the Nigaṇṭha of the Nāta clan, he said: “A Nigaṇṭha, O king (a man free from bonds), is restrained with a fourfold self-restraint. He lives restrained as regards all water; restrained as regards all evil; all evil has he washed away; and he lives suffused with the sense of evil held at bay. Such is his fourfold self-restraint. And since he is thus tied with this fourfold bond, therefore is he, the Nigaṇṭha (free from bonds), called Gatatto (whose heart has gone; that is, to the summit, to the attainment, of his aim) Yatatto (whose heart is kept down; that is, is under command), and Ṭhitatto (whose heart is fixed).”
‘Thus, Lord, did the Nigaṇṭha of the Nāta clan, when asked what was the immediate advantage in the life of a recluse, expound his theory of the fourfold bond.