1.1.15 and 16
तमब्रवीत् प्रीयमाणो महात्मा वरं तवेहाद्य ददानि भूयः। तवैव नाम्ना भविताऽयमग्निः शृङ्कां चेमामनेकरूपां गृहाण ॥१५॥
The great soul, being pleased, said to him: “Here today I grant you another boon. This fire shall be known by your name alone. Take this jewelry chain of intricate forms.”
त्रिनाचिकेतः त्रिभिरेत्य सन्धिं त्रिकर्मकृत् तरति जन्ममृत्यू। ब्रह्मजज्ञं देवमीड्यं विदित्वा निचाय्येमां शान्तिमत्यन्तमेति ॥१६॥
He who performs the threefold Nāciketa fire, having touched by threefold means, and the threefold actions, having approached and known the praiseworthy God who knows Brahman, crosses over birth and death, and, having rightly established this, attains supreme peace.
Bhāṣy 1.1.15 and 16
Threefold means are the path unopposed to the Vedas, and understanding the principles concerning the Lord as taught in the Vedas. The threefold actions are sacrifice, charity, and austerity.
त्रिभिरेत्य सन्धिम् वेदैरविरुद्धः वेदोक्तप्रकारेण भगवत्तत्वादिकं जानन्नित्यर्थः। त्रिकर्मकृत् यज्ञदानतपःकर्ता।
The phrase 'tribhiḥ etya sandhim', i.e. having touched by threefold means, - conveys the path unopposed to the Vedas, and understanding the principles concerning the Lord as taught in the Vedas. A performer of the threefold action is one who engages in sacrifice, charity, and austerity.
"यज्ञदानतपः कर्म न त्याज्यं कार्यमेव तत्।"
"The acts of sacrifice, charity, and austerity must not be abandoned; they are indeed to be performed."
इति वचनात्।
- states the ancient proverb.