'atrer apatyam abhikankshata aha tushto datto mayaham iti yad bhagavan sa dattah' (SB 2.7.4); by the dust of His feet Yadu, Haihaya and others gained the twofold wealth of yoga.
Dattatreya
दत्तात्रेय
Dattatreya is the celebrated yogi-deity of Vaishnava tradition: son of Atri and Anasuya, a partial avatara of Vishnu 'given' (datta) as their child; first guru of the Avadhuta lineage and center of Trimurti worship. SB 1.3.11: the Lord, obtained as Atri's son by Anasuya, taught the anvikshiki to Alarka and to Prahlada and others (the name 'Dattatreya' itself is traditional-universal, not in the verse).
Śrīmad Bhāgavata Mahāpurāṇa 1.3.11 — Sanskrit Wikisource (pinned oldid=369178)
Dattatreya is the son of Atri. Source evidence (SB 1.3.11): He was accepted as Atri's son: 'atrer apatyatvam' (SB 1.3.11). Evidence: EXPLICIT.
Son Anasuya HumanDattatreya is the son of Anasuya. Source evidence (SB 1.3.11): Anasuya obtained Him as her child: 'vrtah prapto 'nasuyaya' (SB 1.3.11). Evidence: EXPLICIT.
Teacher Alarka KingDattatreya is the teacher of Alarka. Source evidence (SB 1.3.11): He taught the anvikshiki to Alarka: 'anvikshikim alarkaya' (SB 1.3.11). Evidence: EXPLICIT.
Teacher Prahlada AsuraDattatreya is the teacher of Prahlada. Source evidence (SB 1.3.11): He taught 'Prahlada and others': 'prahladadibhya ucivan' (SB 1.3.11). Evidence: EXPLICIT.
Sixth: the Lord was obtained as Atri's son by Anasuya: 'sasthe 'trer apatyatvam vrtah prapto 'nasuyaya' (SB 1.3.11); 'Dattatreya' is the universal traditional name of this sixth avatara. Evidence: assumption EXPLICIT; name STRONG_CONTEXT.
The doctrine He taught was the anvikshiki (spiritual inquiry): 'anvikshikim... ucivan' (SB 1.3.11). Evidence: EXPLICIT.