Unnai ariyatha moorkarai ullam iruthu, Unnai arindavarkku inbam peruga, Unnai arindavar tham thalaivan, Unnai arindavar allathavarkku arivaana, * Aadhiyum anthamum illaa arun jothi thaanae. *
However, there are two strong possibilities for what you are referring to. The most likely is (திருச்சழல்) also known as "Thirunamach Chazhal" – a famous hymn by Manikkavasagar in the Thiruvasagam that focuses entirely on chanting the names of Shiva. Thirunama Pathigam Lyrics In English
After a thorough search of canonical Tamil Saiva Siddhanta literature (Manikkavasagar's Thiruvasagam, Appar, Sundarar, Sambandar's Thevaram), . Unnai ariyatha moorkarai ullam iruthu