Book 3 starts with the invocation to the holy Light, treated by Milton both as the first thing created by God and also as a kind of God’s attribute. The poet expresses his happiness that he can now switch the subject from the gloom and doom of Hell to the light of Heaven. But unfortunately for him, being blind, he really cannot see the light and it is left to his imagination at night. (Like many blind people, Milton suffered from insomnia and he composed most of Paradise Lost in his head, lying awake at night and then dictating to his amanuenses in the morning. He finds solace in remembering other real or legendary blind bards: Homer, of course, whom he calls by his nickname “Maeonides” (either to keep the rhythm of the verse or just to show off), another blind Greek poet Thamyris, and mythological Tiresias and Phineus. He compares himself to a nightingale, singing only in the dark. Seasons may change but he can’t see it, and the great book of nature remains to him a blank, writes Milton in what are to me the most personal and touching lines of the poem up to this point. Thus, he asks celestial Light for even more enlightenment, to plant eyes in his soul.
God the Father is sitting on his throne, with his Son on his right hand, surrounded by angels. He sees perfectly the earth and the happy first parents living there still in perfect harmony. He also sees Satan hovering around the walls of the new universe and wondering in which place to cross. He sees past, present and future (which poses a lot of mind-bending questions, but Milton chooses not to address them at this point and neither shall we). He points out Satan to his Son, telling him how vengeful he is that even the walls of Hell can’t contain him