Tirumurai: Twelve Periapuranam (Thiruthondar Puranam) chEkkizAr (Sekilaar) worshiped Lord Nataraja at chithambaram. Lord Siva gave him the first word to start the epic as "Ukagelam"
Ulakelaam unarn thoathar kariyavan
nilavu laaviya neermali vae'niyan
alakil jothiyan ampalath thaaduvaan
malarsi lampadi vaalthi va'nangkuvaam.
He who is rare to be comprehended
And expressed in words by all the worlds;
In His crest rest the crescent and the flood;
Limitless is His effulgence;
He dances in the Ambalam.
We hail and adore His ankleted flower-feet.
Another version of Translation
The One, Who is difficult for the world to experience and explore out !
The One with moon wandering, water brimming Hair !
Illuminant beyond any scales (to measure) !
Dances in the common (thirucciRRambalam hall) !
His Floral cilambu ornamented Feet, (we) hail, salute !!