In plain words
The poet, to the Lord: When was it that the ocean [of milk] was churned? Which world was it you received with the poured water of a gift [from Mahābali]? Of that I understand nothing at all. That ocean is the one you dammed that day [as Rāma] and broke again, and the one you lie upon in sleep; this earth is the one you made, dug up [as Varāha], swallowed [at the deluge] and brought out again.