yuga-avatāra - incarnation of millenniums; ebe - now; śuna - hear; sanātana - O Sanātana Gosvāmī; satya-tretā-dvāpara-kali-yugera - of Satya-yuga, Tretā-yuga, Dvāpara-yuga and Kali-yuga; gaṇana - the chronological order.

“O Sanātana, now hear from Me about the yuga-avatāras, the incarnations for the millenniums. First of all, there are four yugas — Satya-yuga, Tretā-yuga, Dvāpara-yuga and Kali-yuga.