śiva gāyatrī mantraḥ

The Shiva Gayatri — a single verse in the gayatri metre, built on the pattern the Vedic Gayatri established and repeated for every deity who has one: we know Mahadeva, we meditate on the form of Rudra; may Shiva impel us onward. Its three clauses do the three things such a mantra always does, name the god, fix the meditation, and ask for the impulse rather than for a gift. It is repeated as japa rather than read as a hymn, most often at the junctures of the day and before other Shaiva recitations, and its brevity is the reason it is used that way — it can be told on a rosary a hundred and eight times without the reciter losing the thread.