§ Of the Beginning of Days The Silmarillion

In that time the Valar brought order to the seas and the lands and the mountains, and Yavanna planted at last the seeds that she had long devised. And since, when the fires were subdued or buried beneath the primeval hills, there was need of light, Aulë at the prayer of Yavanna wrought two mighty lamps for the lighting of the Middle-earth which he had built amid the encircling seas. Then Varda filled the lamps and Manwë hallowed them, and the Valar set them upon high pillars, more lofty far than are any mountains of the later days. One lamp they raised near to the north of Middle-earth, and it was named Illuin; and the other was raised in the south, and it was named Ormal; and the light of the Lamps of the Valar flowed out over the Earth, so that all was lit as it were in a changeless day.