What language does the original text of the Rubaiyat of Omar Khayyam use?

The Persian Poet: Omar Khayyam

Omar Khayyam, born in 1048 AD, was a Persian polymath, philosopher, mathematician, astronomer, and most importantly, a poet. He is best remembered for his collection of quatrains called the Rubaiyat, which are four-line stanzas with each line comprising of two hemistichs (half-lines) with a particular rhythm and rhyme scheme. Khayyam's work was written almost nine centuries ago, and it was in the literary and cultural language of the time: Persian.