Yuga-Vibhāga and Kāla-Pramāṇa
Measures of Time and the Four Yugas
श्रौत स्मार्त्त च ते धर्म ब्रह्मणानुप्रचौदितम् / दाराग्निहोत्रसंबन्धमृग्यजुः सामसंहितम्
śrauta smārtta ca te dharma brahmaṇānupracauditam / dārāgnihotrasaṃbandhamṛgyajuḥ sāmasaṃhitam
Their dharmas—both Śrauta and Smārta—were enjoined by Brahmā: the duties bound to household life and the Agnihotra, together with the Saṃhitās of Ṛg, Yajus, and Sāma.