§ Of the Flight of the Noldor The Silmarillion

Yavanna spoke before the Valar, saying: "The Light of the Trees has passed away, and lives now only in the Silmarils of Fëanor. Foresighted was he! Even for those who are mightiest under Ilúvatar there is some work that they may accomplish once, and once only. The Light of the Trees I brought into being, and within Eä I can do so never again. Yet had I but a little of that light I could recall life to the Trees, ere their roots decay; and then our hurt should be healed, and the malice of Melkor be confounded.'