Manava Dharmashastra 1.87

1.87

uktaḥ kālavibhāgaḥ | brāhmaṇādīnāṃ guṇā idānīṃ kathyante | tatrāyamupakramaḥ | sarvasya sargasya sarveṣāṃ lokānāṃ guptyarthaṃ rakṣārtham | mahātejāḥ prajāpatiḥ mukhādijātānāṃ brāhmaṇādīnāṃ caturṇāṃ varṇānāṃ dṛṣṭādṛṣṭārthāni karmāṇyakalpayad vyavasthāpitavān |

With a view to the protection of this entire creation, the Resplendent One ordained the distinct functions of those who sprang from the mouth, the arms, the thighs and the feet—(86).

Medhātithi’s commentary (manubhāṣya):
The divisions of time have been described. The qualifications of the Brāhmaṇa and the other people are now described; and the present verse serves as an introduction to that subject.

‘Of this entire creation,’—i.e., of all beings,—‘with a view to the protection’—for the purpose of their safety;—the Resplendent One, Prajāpati,—‘ordained,’—distributed—‘the functions,’—i.e., actions, leading to perceptible as well as imperceptible results,—of the Brāhmaṇa and other castes, that sprang from his mouth and other limbs. (87).