Lhûg!
Anno i-tlhaes enni!
Ed geryth ú-bennan a guid arnoediad
Maethannen a mudassen,
Nas vedui telin.
Radannen sí n' i-dorech gîn
athan i-Orthond-en-eirech
An edraith e-'laes i mabanneg.
An i-innas nîn velt sui i-faer gîn,
a i-charnad nîn sui veleg.
Leitho hon, ulund!
Ú-'erig valan or nin.
.
Snake!
Give me the child!
Through horrors unspeakable and foes unnumbered
I have fought and I have labored,
At last I am come.
I have made my way here to your lair
Beyond the Goblin City
To take back the child that you have stolen.
For my will is as strong as yours, and my kingdom is as great.
Release him, monster!
You have no power over me.
Literally:
Snake!
Give the-child to-me!
Out-of-horrors unspoken and foes without-number
I-have-come and I-have labored,
At last I-come.
I-made-my-way here to the-lair yours
Beyond the-city-of-[the]-Goblins
For the saving of-the-child who you-have seized.
For the-heart mine strong [is] as the-spirit yours,
And the-kingdom mine [is] as great.
Release him, monster!
Not-possess-you power over me.
Original Sindarin/English poetry and translation from Jim Henson's Labyrinth, 1986: "Give me the child. Through dangers untold and hardships unnumbered, I have fought my way here to the castle beyond the Goblin City to take back the child that you have stolen. For my will is as strong as yours, and my kingdom is as great...You have no power over me."
Inspired by Elendil's Oath [RotK]: "Out of the Great Sea to Middle-earth I am come. In this place I will abide, and my heirs, unto the ending of the world."
Sources:
1) Hiswelókë's Sindarin-English Dictionary: "Strict" Sindarin & Noldorin Alphabetical and Analogical Dictionaries.
2) Thorsten Renk's Pedin Edhellen, a Sindarin-Course, Version 3.05