In Saiva Siddhantha, this is THE book. Many have never heard of it. Full of lofty talk of Siva, it contains over 3000 verses in Tamil. Its author. Tirumoolar, is renowned amongst the Tamil Siddhars. Said to have come from the Himalayas, and not knowing Tamil, he took over the body of a cowherd. It reads somewhat like the Upanishads
Here's a sampling ... Verse 2807
"He is the Light Cosmic,
He is the Light Beyond.
He is the Light that mingles in the Light within,
In the spreading light of space,
That swallows Immensity vast,
My body-light merged:
Shattering Existence's landmarks, all."
Taken from the Ramakrishna Mission translation, published 1991
Here's a sampling ... Verse 2807
"He is the Light Cosmic,
He is the Light Beyond.
He is the Light that mingles in the Light within,
In the spreading light of space,
That swallows Immensity vast,
My body-light merged:
Shattering Existence's landmarks, all."
Taken from the Ramakrishna Mission translation, published 1991