kalpanta idam adaya
sayane ’mbhasy udanvatah
vivise ’ntar aham vibhoh
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
At the end of the millennium, when the Personality of Godhead, Lord Narayana, lay down within the water of devastation, Brahma began to enter into Him along with all creative elements, and I also entered through His breathing.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Narada is known as the son of Brahma, as Lord Krsna is known as the son of Vasudeva. The Personality of Godhead and His liberated devotees like Narada appear in the material world by the same process. As it is said in the Bhagavad-gita, the birth and activities of the Lord are all transcendental. Therefore, according to authorized opinion, the birth of Narada as the son of Brahma is also a transcendental pastime. His appearance and disappearance are practically on the same level as that of the Lord. The Lord and His devotees are therefore simultaneously one and different as spiritual entities. They belong to the same category of transcendence.