With the light created by the blessed Holy One on the first day, one could gaze and see from one end of the universe to the other.
— Zohar (ZP I.45)
The light created at the very beginning is not the same as the light emitted by the sun, the moon, and the stars, which appeared only on the fourth day. The light of the first day was of a sort that would have enabled man to see the world at a glance from one end to the other. Anticipating the wickedness of the sinful generations of the deluge and the Tower of Babel, who were unworthy to enjoy the blessing of such light, God concealed it, but in the world to come it will appear to the pious in all its pristine glory.
— Haggadah (Barnstone 1984, 16)
The ‘world to come’ is the Firstness of the world apocalyptically revealed in all its pristine glory.