§ Of Fëanor and the Unchaining of Melkor The Silmarillion

Before the gates of Valmar Melkor abased himself at the feet of Manwë and sued for pardon, vowing that if he might be made only the least of the free people of Valinor he would aid the Valar in all their works, and most of all in the healing of the many hurts that he had done to the world. And Nienna aided his prayer; but Mandos was silent