Arabic prosody

ʿArūḍ or arud (Arabic: اَلْعَرُوض‎‎ al-ʿarūḍ) is often called the Science of Poetry (Arabic: عِلْم اَلشِّعْر‎‎ ʿilm aš-šiʿr). Its laws were laid down by Al-Khalil ibn Ahmad al-Farahidi (d. 786), an early Arab lexicographer and philologist, who did so after noticing that poems consisted of repeated rhythms in each verse. He wrote his first book, Al-Ard, describing 15 types of verses. It is said that he used to climb down into a well in order to enjoy the poems during his study. Later Al-Akhfash al-Akbar described a 16th meter, al-Mutadārik.

Al-Khalil was primarily a grammarian, and using the grammatical terminology of his day he employed the terms ḥarf mutaḥarrik "mobile letter" and ḥarf sākin "quiescent letter" to devise a classification of syllables. A ḥarf mutaḥarrik is a consonant which is followed by a vowel, and a ḥarf sākin is a consonant which is not followed by a vowel. He combined these as fundamental prosodic elements to define a number of prosodic sequences.

ʿArūḍ is the study of poetic meters, which identifies the meter of a poem and determines whether the meter is sound or broken in lines of the poem. The study of ʿarūḍ is said to have begun within the first century AH in a region called ʿArūḍ near Mecca in Arabia, which is why it was called ʿarūḍ.

...
Wikipedia