§ Of Beren and Lúthien The Silmarillion

In that time Thingol turned to Melian; but now she withheld her counsel from him, saying that the doom that he had devised must work to its appointed end, and that he must wait now upon time. But Thingol learned that Lúthien had journeyed far from Doriath, for messages came secretly from Celegorm, as has been told, saying that Felagund was dead, and Beren was dead, but Lúthien was in Nargothrond, and that Celegorm would wed her. Then Thingol was wrathful, and he sent forth spies, thinking to make war upon Nargothrond; and thus he learned that Lúthien was again fled, and that Celegorm and Curufin were driven from Nargothrond. Then his counsel was in doubt, for he had not the strength to assail the seven sons of Fëanor; but he sent messengers to Himring to summon their aid in seeking for Lúthien, since Celegorm had not sent her to the house of her father, nor had he kept her safely.