SB 5.15.6
bhumna rsikulyayam udgithas tatah prastavo devakulyayam prastavan niyutsayam hrdayaja asid vibhur vibho
ratyam ca prthusenas tasman nakta akutyam jajñe naktad druti-putro gayo rajarsi-pravara udara-srava ajayata
saksad bhagavato visnor jagad-riraksisaya grhita-sattvasya kalatmavattvadi-laksanena maha-purusatam praptah.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
In the womb of his wife, Rsikulya, King Bhuma begot a son named Udgitha. From Udgitha’s wife, Devakulya, a son named Prastava was born, and Prastava begot a son named Vibhu through his wife, Niyutsa. In the womb of his wife, Rati, Vibhu begot a son named Prthusena. Prthusena begot a son named Nakta in the womb of his wife, named Akuti. Nakta’s wife was Druti, and from her womb the great King Gaya was born. Gaya was very famous and pious; he was the best of saintly kings. Lord Visnu and His expansions, who are meant to protect the universe, are always situated in the transcendental mode of goodness, known as visuddha-sattva. Being the direct expansion of Lord Visnu, King Gaya was also situated in the visuddha-sattva. Because of this, Maharaja Gaya was fully equipped with transcendental knowledge. Therefore he was called Mahapurusa.
Purportby His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
From this verse it appears that the incarnations of God are various. Some are part and parcel of the direct expansions, and some are direct expansions of Lord Visnu. A direct incarnation of the Supreme Personality of Godhead is called amsa or svamsa, whereas an incarnation from amsa is called kala. Among the kalas there are the vibhinnamsa-jivas, or living entities. These are counted among the jiva-tattvas. Those who come directly from Lord Visnu are called visnu-tattva and are sometimes designated as Mahapurusa. Another name for Krsna is Mahapurusa, and a devotee is sometimes called maha-paurusika.