Manava Dharmashastra 1.75

1.75

uktā'pyeṣā tattvasya sṛṣṭiḥ | yo viśeṣo noktastatpratipādanāya punarucyate | vikurute viśeṣataḥ karoti brahmaṇā codyamānam | tasmāccoditādākāśaṃ jāyate | tasyākāśasya śabdākhyo guṇo bhavati | guṇa āśrita ucyate, ākāśaṃ tasyāśrayaḥ | na hyākāśaṃ vinā śabdasya sambhavaḥ |

The ‘Mind’ impelled by (Brahmā’s) desire to create, evolves creation;—from out of that (Mind) is produced Ākāśa; of this they know sound to be the quality.—(75)

Medhātithi’s commentary (manubhāṣya):
Though the creation of the ‘Principles’ has been already described, it is stated again for the purpose of pointing out the details not set forth before.

Vikurute, ‘evolves,’—i.e., being impelled, by Brahmā, it brings about creation in a particular manner;—from out of the ‘Mind’ (i.e., the Great Principle of Intelligence), thus propelled (to modification) is produced Ākāśa; and this Ākāśa possesses the quality known as ‘Sound ‘Quality’ is that which subsists (in a substance); and the substratum of the quality of Sound is Ākāśa, in the sense that no Sound is possible apart from Ākāśa.—(75)