Text:

त्रिणाचिकेतस्त्रयमेतद्विदित्वा य एवं विद्वाँश्चिनुते नाचिकेतम् ।
स मृत्युपाशान्पुरतः प्रणोद्य शोकातिगो मोदते स्वर्गलोके ॥ १८ ॥

triṇāciketastrayametadviditvā ya evaṃ vidvām̐ścinute nāciketam |
sa mṛtyupāśānpurataḥ praṇodya śokātigo modate svargaloke || 18 ||

18. The three-fold Nachiketas, knowing these three, who propitiates the Nachiketa fire with this knowledge, casts off Death’s meshes behind him, travels beyond grief and rejoices in heaven.

Shankara’s Commentary:

He now concludes the fruits, of the knowledge and the performance of sacrifice and with them, the present topic. The three-fold Nachiketas who properly understands what was said about the bricks, their numbers and mode and who realizing the fire as the atman completes the sacrifice called Nachiketa, shakes off even before death, the meshes of Death consisting in vice, ignorance, desire and hatred, etc., and devoid of all grief rejoices in heaven, i.e., by realizing his Self as the virat.