Manava Dharmashastra 6.31

6.31

prācyā udīcyāśca diśorantarālamaparājitā dik lokeṣvaiśānītyucyate | diśamāsthāya | cetasi vidhāya 'eṣā mayā gantavyeti' tatastāmeva vrajet |
ajihmagaḥ akuṭilagāmī | śvabhranadīsrotāṃsi na pariharet |
ā nipātāccharīrasya yukto vāryanilāśanaḥ | prācyā udīcyāśca gamanavidhirayam | yāvanna patati tāvadvāyubhakṣo'mbubhakṣaśca syāt | yuktaḥ yogaśāstrairātmānaṃ yuktvā |
tadetanmahāprasthānamucyate |

Medhātithi’s commentary (manubhāṣya):
The ‘Aparājitā’ is the name of the North-Easterly direction, known among the people as ‘Aiśānī’;—‘Having fixed upon’ this direction—as “this is the direction towards which I shall go’,—he should proceed towards it.

‘Moving straight on’—not swerving from his path, not seeking to avoid even rivers and streams. This is a rule laying down the going towards the North-East.

‘Intent, living upon water and air, till the falling off of the body.’—That is, until the body falls off, he shall live upon air and on water.

‘Intent’,—having concentrated himself by the rules of Yoga.

This refers to the ‘Grand Journey’ (towards certain death).—(31).