It is of the most ancient form
and tells of those three houses
They who fought the Dark til ne'er lost
who risked all with their brothers no matter the cost
A heroic voyage enable them to survive the dire test
and in return they were given the west.
Akallabeth
(Another source indicates Narn i Hin Hurin)
The Akallabêth is the story of the destruction of the realm of Númenor.
Akallabeth (probably this one), Tale of the chilren of Hurin (Narn I Hin Hurin), Release from Bondage (Lay of Leithan)
First line of the riddle, "It is in the most ancient form", was listed as "It is in the most ancient form" on another source. Which is correct?
Tolkien Gateway: Akallabêth