Srimad Bhagavatam Canto 04, Chapter 15, Text 06

SB 4.15.6

esa saksad dharer amso
jato loka-riraksaya
iyam ca tat-para hi srir
anujajñe ’napayini
 
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
In the form of King Prthu, the Supreme Personality of Godhead has appeared through a part of His potency to protect the people of the world. The goddess of fortune is the constant companion of the Lord, and therefore she has incarnated partially as Arci to become King Prthu’s queen.
 
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
 
In Bhagavad-gita the Lord says that whenever one sees an extraordinary power, he should conclude that a specific partial representation of the Supreme Personality of Godhead is present. There are innumerable such personalities, but not all of them are direct visnu-tattva plenary expansions of the Lord. Many living entities are classified among the sakti-tattvas. Such incarnations, empowered for specific purposes, are known as saktyavesa-avataras. King Prthu was such a saktyavesa-avatara of the Lord. Similarly, Arci, King Prthu’s wife, was a saktyavesa-avatara of the goddess of fortune.
Srimad Bhagavatam Canto 04, Chapter 15, Text 05
Srimad Bhagavatam Canto 04, Chapter 15, Text 07