But now a cry went up, passing up the wind from the south from vale to vale, and Elves and Men lifted their voices in wonder and joy. For unsummoned and un-looked for Turgon had opened the leaguer of Gondolin, and was come with an army ten thousand strong, with bright mail and long swords and spears like a forest. Then when Fingon heard afar the great trumpet of Turgon his brother, the shadow passed and his heart was uplifted, and he shouted aloud:
'Utúlie'n aurë! Aiya Eldalië ar Atanatári, utúlie'n aurë!' (The day has come! Behold, people of the Eldar and Fathers of Men, the day has come!)
And all those who heard his great voice echo in the hills answered crying:
'Auta i lómë!' (The night is passing!)
...
Then in the plain of Anfauglith, on the fourth day of the war, there began Nirnaeth Arneodiad, Unnumbered Tears, for no song or tale can contain all its grief.
(Quenta Silmarillion)