SB 1.3 - Kapila, Dattātreya and Yajña
(5) Lord Kapila is foremost among perfected beings. He had a brown complexion and thus was called Kapila by Brahmā. He gave an exposition on the creative elements and metaphysics to Āsuri Brāhmaṇa. There are 24 elements in all. Each and every element is explained in Sāṅkhya philosophy, which explains very lucidly by analysis of material elements.
(6) Dattātreya appeared as the son of Atri and Anasūyā. He spoke on the subject of transcendence to Alarka, Prahlāda and others. Anasūyā prayed before the lords Brahmā, Viṣṇu and Śiva that they combine together to become her son. Thus Dattātreya was born. He is so called because the Lord being pleased with Atri said ‘I have given myself to you’.
(7) The Lord appeared as Yajña, the son of Prajāpati Ruci and his wife Ākūti. He controlled the period during the reign of the Svāyambhuva Manu and was assisted by demigods called Yamas, who were His sons. During the period of Svāyambhuva Manu there was no suitable living being who could occupy the post of Indra. The Lord Himself at that time became Indra and ruled the administration of universal affairs.