SB 1.3.11
sastham atrer apatyatvam
vrtah prapto ’nasuyaya
anviksikim alarkaya
prahladadibhya ucivan
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The sixth incarnation of the purusa was the son of the sage Atri. He was born from the womb of Anasuya, who prayed for an incarnation. He spoke on the subject of transcendence to Alarka, Prahlada and others [Yadu, Haihaya, etc.].
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The Lord incarnated Himself as Dattatreya, the son of Rsi Atri and Anasuya. The history of the birth of Dattatreya as an incarnation of the Lord is mentioned in the Brahmanda Purana in connection with the story of the devoted wife. It is said there that Anasuya, the wife of Rsi Atri, prayed before the lords Brahma, Visnu and Siva as follows: “My lords, if you are pleased with me, and if you desire me to ask from you some sort of blessings, then I pray that you combine together to become my son.” This was accepted by the lords, and as Dattatreya the Lord expounded the philosophy of the spirit soul and especially instructed Alarka, Prahlada, Yadu, Haihaya, etc.