SB 7.11.5
sri-narada uvaca
natva bhagavate ’jaya
lokanam dharma-setave
vaksye sanatanam dharmam
narayana-mukhac chrutam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Sri Narada Muni said: After first offering my obeisances unto Lord Krsna, the protector of the religious principles of all living entities, let me explain the principles of the eternal religious system, of which I have heard from the mouth of Narayana.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The word aja refers to Krsna, who explains in Bhagavad-gita (4.6), ajo ’pi sann avyayatma: “I am ever existing, and thus I never take birth. There is no change in My existence.”