§ Of Tuor and the Fall of Gondolin The Silmarillion

The wise have said that the hour was not yet come, and that only one speaking in person for the cause of both Elves and Men, pleading for pardon on their misdeeds and pity on their woes, might move the counsels of the Powers; and the oath of Fëanor perhaps even Manwë could not loose, until it found its end, and the sons of Fëanor relinquished the .Silmarils, upon which they had laid their ruthless claim. For the light which lit the Silmarils the Valar themselves had made.