The Declaration of Ilúvatar and the creation of the World that Is

Mighty are the Ainur, and mightiest among them is Melkor; but that he may know, and all the Ainur, that I am Ilúvatar, those things that ye have sung, I will show them forth, that ye may see what ye have done. And thou, Melkor, shalt see that no theme may be played that hath not its uttermost source in me, nor can any alter the music in my despite. For he that attempteth this shall prove but be mine instrument in the devising of things more wonderful, which he himself hath not imagined.

Ilúvatar showed to the Ainur a vision of their song, giving to them sight where before was only hearing: and they saw a new World made visible before them, and it was globed amid the void. "Behold your Music! This is your minstrelsy" said Ilúvatar, "Eä! Let these things Be" and he sent forth the Flame Imperishable and gave life and being to this vision. And suddenly the Ainur saw afar off a light, as it were a cloud with a living heart of flame; and they knew that this was no vision only, but that Ilúvatar had made a new thing : Eä, the World that Is.

Thus it came to pass that of the Ainur some abode still with Ilúvatar beyond the confines of the World, but others, and among them many of the greatest and most fair, took the leave of Ilúvatar and descended into it.