Its laws were laid down by Al-Khalīl ibn Aḥmad al-Farāhīdī (d. 786), an early Arab lexicographer and philologist.
In his book Al-ʿArḍ (Arabic: العرض), which is no longer extant, he described 15 types of meter.
Certain meters also have biceps positions where a pair of short syllables can optionally be replaced by a long one.
The great majority (85-90%) of early classical Arabic poetry is composed in just four meters: the ṭawīl (which is the most common), the kāmil, the wāfir and the basīṭ.
The feet of an Arabic poem are traditionally represented by mnemonic words called tafāʿīl (تفاعيل).
Among the 1385 short poems included in the Arabian Nights, ṭawīl is used in 24%, basīṭ 24%, kāmil 23%, wāfir 10%, ramal 2%, rajaz 2%, xafīf 5%, sarīʿ 4%, munsarih 1%, mujtatt 1%, and mutaqārib 3%.
[10] The mutadārik breaks almost all regular rules of meter, however it was highly regarded by Arabic Grammarians in the 10th century CE, and was noted for its eloquence.
Its earliest attestation is in the 7th century CE by Amr Bin Jabir Al Jani in a poem for praise of the prophet: أشَجاكَ تَشَتُّتُ شِعْبِ الحَيِّ == فأنْتَ لَهُ أرِقٌ وَصِبُThe collated figures can be expressed in a table as follows: Al-Khalil was primarily a grammarian and using the grammatical terminology of his day he made use of the terms ḥarf mutaḥarrik "mobile letter" (i.e. one followed by a vowel) and ḥarf sākin "quiescent letter" (i.e. one not followed by a vowel) to build up larger prosodic units, which he called "peg" (watid or watad, pl.
[13] The watid is repeated at fixed points along the line and is generally unchanging, while the asbāb or cords are the syllables in between which could be modified.
When analysing a verse, an Arab prosodist begins by rewriting the line phonetically, that is, as it is actually pronounced.
A line of poetry, known as a bayt (بيت "tent"), is composed of two half-lines or hemistichs, each of which is known as a miṣrāʿ (مصراع "door-flap").
Expressed in terms of syllables rather than Khalil's silent and moving letters, the different circles can be tabulated as follows.
[22] For example, if the foot mustafʿilun (– – u –) is replaced by mafāʿilun (u – u –), it is said to be maxbūn, that is, it has undergone the ziḥāf known as xabn "hemming" or "shortening".
If the line-ending mustafʿilun (– – u –) is replaced by mustafʿil (– – –) that is, if the line is catalectic, the meter is said to be maqṭūʿ, that is, it has undergone the ʿilla known as qaṭʿ "cutting" or "curtailment".
There are a number of prosodic conventions which are observed in writing and scanning Arabic poetry, of which the following are the most important:[23]