Arabic poetry (Arabic .ash-shi‘ru al-‘Arabīyu) is the earliest form of Arabic literature. Present knowledge of poetry in Arabic dates from the 6th century, but oral poetry is believed to predate that. Arabic poetry is categorized into two main types, rhymed or measured, and prose, with the former greatly preceding the latter. The rhymed poetry falls within fifteen different meters collected and explained by al-Farahidi in The Science of ‘Arud. Al-Akhfash, a student of al-Farahidi, later added one more meter to make them sixteen. The meters of the rhythmical poetry are known in Arabic as "seas" (buḥūr). The measuring unit of seas is known as "taf‘īlah", and every sea contains a certain number of taf'ilas which the poet has to observe in every verse.(bayt) of the poem. The measuring procedur