From The Rubaiyat of Omar Khayyam

Rubaiyat of Omar Khayyam (Persian: رباعیات عمر خیام) is the title that Edward FitzGerald gave to his translation of a selection of poems, originally written in Persian and of which there are about a thousand, attributed to Omar Khayyám (1048--1131), a Persian poet, mathematician and astronomer. A Persian ruba'i is a two line stanza with two parts (or hemistechs) per line, hence the word "Rubaiyat", (derived from the Arabic root word for 4), meaning "quatrains".