Manava Dharmashastra 1.53

1.53

pūrvavyākhyānaśloko'yaṃ vispaṣṭārthaḥ | svasthe susthire | śāntātmavacchuddharūpe | svātmanyavasthānamaupādhikabhedattiḥ | karmātmānaḥ karmapradhānāḥ saṃsāriṇaḥ kṣetrajñāḥ | śarīriṇaḥ | karmasambandhena śarīrasambandhānubhavādevamucyante | tasminsvapati śayāne svakarmabhyo nivartante | śarīraceṣṭānivṛttiretenocyate | manaśca glānimṛcchati | etenāntaravyāpāranivṛttiḥ | ato bāhyāntaravyāpāranivṛttyā pralayaḥ pratipādito bhavati | glānirnirutsāhaḥ svavyāpāre'śaktatāmṛcchati prāpnoti |

Medhātithi’s commentary (manubhāṣya):
The meaning of this verse is quite clear, its meaning having been already explained.

‘Having retired within himself’—i.e., in calm repose, i e., in pure pristine nature of the Soul at rest;—‘retiring within himself’ stands for the cessation of all accidental diversities.

‘Active’—the conscious beings who are fallen in the cycle of births and deaths, and for whom Action is of the greatest importance;—‘embodied beings,’—so called because they feel the effects of being connected with a body which is the effect of their own past acts.

‘When he slumbers,’ all these ‘desist from their actions,’—this stands for the cessation of their bodily activity;—‘their mind falls into depression’—this stands for the cessation of their mental activity. Thus this cessation of bodily and mental activities indicates the state of Dissolution.—‘Depression’ means absence of energy, disability to carry on its functions; this is what the Mind falls into,—attains.—(53)