§ Of the Ruin of Doriath The Silmarillion

Unhappy was the lot of Húrin; for all that Morgoth knew of the working of his malice Húrin knew also, but lies were mingled with the truth, and aught that was good was hidden or distorted. In all ways Morgoth sought most to cast an evil light on those things that Thingol and Melian had done, for he hated them, and feared them. When therefore he judged the time to be ripe, he released Húrin from his bondage, bidding him go whither he would; and he feigned that in this he was moved by pity as for an enemy utterly defeated. But he lied, for his purpose was that Húrin should still further his hatred for Elves and Men, ere he died.