Disclaimer: The Oath is from The Lays of Beleriand I DO NOT OWN THE OATH. I BORROWED IT!
# 68 Oaths
Filled with a new rage after the death and burial of his father Finwë, Fëanor swiftly ran back to Tirion. Even though the Valar had not lifted the ban on his exile, he cared not, he was going to avenge his father and reclaim the Silmarils, and no one including the Valar was going to stop him!
As he arrived in Tirion with a torch in his hands, Fëanor stood on a platform and got everyone's attention––Elves and Valar alike. They could tell by the look of rage in his eyes he was serious and nobody was brave enough to stop him; not even the Valar interfered at this point.
Fëanor spoke with such authority about how they were being held prisoner here in Valinor when they could instead rule kingdoms of their own back in Middle-earth. "The Valar are jealous and unable even to keep us safe from their enemy," he sneered, "you should help avenge your king––my father––who died as a result of their failure!" At this point, all the Noldor were beginning to agree and started murmuring against the Valar.
At the end of his speech Fëanor took an Oath, which his sons hearing their father came to his side and made the same oath:
"Be he foe or friend, be he foul or clean
Brood of Morgoth or bright Vala,
Elda or Maia or Aftercomer,
Man yet unborn upon Middle-earth,
Neither law, nor love, nor league of swords,
Dread nor danger, not Doom itself
Shall defend him from Fëanáro, and Fëanáro's kin,
Whoso hideth or hoardeth, or in hand taketh,
Finding keepeth or afar casteth
A Silmaril. This swear we all…
Death we will deal him ere Day's ending,
Woe unto world's end! Our word hear thou,
Eru Allfather! To the everlasting
Darkness doom us if our deed faileth…
On the holy mountain hear in witness
and our vow remember,
Manwë and Varda!
There was no turning back. The sons' of Fëanor and Fëanor himself were now bound to the Oath and the consequences that would follow.