The following was Found entirely within The Lord of the Rings.
For Evermind, who inspired and encouraged me, and for Primula, who guided me through an unfamiliar territory.
A Flash of Silver
Shadowfax the Great, prince of horses,
Descended from the free days of old,
True and valiant, a noble beast that might have been
Foaled in the morning of the world.
I have not seen his like before.
Were the breath of the West Wind to take a body visible,
Even so would it appear:
By day his coat glistens, shining like silver in the sunlight;
By night it is like a shade, and he passes unseen,
A shadow among the willows.
The meaning of haste: like an arrow from the bow,
A flash of silver and white, running wild over the grass,
His mane flowing in the wind of his speed;
Only a swift bird on the wing could vie with him.
Light is his footfall!
No sign of road or track through the endless miles of grass,
But Shadowfax knows the way through every fen and hollow
Between the Misty Mountains and the White,
From the shadow of Tol Brandir
To the fords of the Isen.
Shadowfax is wild and will let no man handle him,
But a great friendship has grown between us,
And if I have need he will come at my call.