According to Sri Lankan Buddhist tradition, the Rathnamali Gatha holds deep historical and mystical significance. It is traditionally believed that the great King Dutugemunu (who ruled Sri Lanka in the 2nd Century BCE) had these verses inscribed on the relic chamber of the Ruwanweli Maha Seya (the Great Stupa) in Anuradhapura.
This Yanthraya is a string of Pali words that are chanted repeatedly, often with a focus on the syllables (සං) and "Lam" (ලං). The following is a standard Pali version of the Rathnamali Yanthraya text: rathnamali gatha pdf
For those seeking a deep study of the text and its Sinhala meanings, several resources provide the full lyrics and translations: According to Sri Lankan Buddhist tradition, the Rathnamali