These drabbles were written for Tolkien_weekly's "Let There Be Light" challenge.
"[Melkor] had gone often alone into the void places seeking the Imperishable Flame; for desire grew hot within him to bring into Being things of his own, and it seemed to him that Ilúvatar took no thought for the Void, and he was impatient of its emptiness" ("Ainulindalë," Silmarillion).
"But when they were come into the Void, Ilúvatar said to them: 'Behold your Music!' And he showed to them a vision, giving to them sight where before was only hearing [...]" ("Ainulindalë," Silmarillion).
Sunlight and Twilight:
"But it was said afterwards among the Eldar that when Men awoke in Hildórien at the rising of the Sun the spies of Morgoth were watchful, and tidings were soon brought to him; and this seemed to him so great a matter that secretly under shadow he himself departed from Angband, and went forth into Middle-earth, leaving to Sauron the command of the War. Of his dealing with Men the Eldar indeed knew nothing, at that time, and learnt but little afterwards [...]" ("Of the Coming of Men into the West," Silmarillion).
"Morgoth had then not long come back into Middle-earth, and his power went not far abroad, and was moreover checked by the sudden coming of great light" ("Of Men," Silmarillion).
Torchlight: "[...] Men (it is said) were at first very few in number, whereas Morgoth grew afraid of the growing power and union of the Eldar and came back to Angband, leaving behind at that time but few servants, and those of less might and cunning" ("Of the coming of Men into the West," Silmarillion).
The Precepts: fanonical sacred text of the Haradrim.
Lamplight: "The heathen kings of old" - Gandalf, "The Pyre of Denethor," RoTK
Candlelight: "the Messengers who came late among them": "Of the Blue little was known in the West, and they had no names save Ithryn Luin 'the Blue Wizards'; for they passed into the East with Curunír, but they never returned, and whether they remained in the East, pursuing there the purposes for which they were sent; or perished; or as some hold were ensnared by Sauron and became his servants, is not now known" ("The Istari," Unifinished Tales). (Thank you, Allie Meril!)