Introduction

The term rubā’ī (quatrain) evokes a poetic form along with its unique meter. If a poem is composed of four hemistiches where the first, second, and fourth hemistiches rhyme but lack the distinctive meter of the rubā’ī, it cannot be considered a rubā’ī, as the identity of this form lies in its specific meter. In Arabic, the rubā’ī (or al-dūbayt) is also recognized by its particular meter. Given that the Arabic rubā’ī was almost certainly derived from the Persian rubā’ī, and considering that metrical features stem from linguistic characteristics - although there are differences between Persian and Arabic prosody - the rubā’ī exhibits significant similarities. These similarities indicate that the Arabic rubā’ī borrowed its meter from the Persian rubā’ī, with poets making only minor adjustments. As a result, it differs from the Khalīlian (classical Arabic) prosodic system. This meter cannot be derived from Khalīl's circles.

Literature Review

It appears that the first comprehensive book written on the rubā’ī (quatrain) is Dīwān al-Dūbayt fī al-Shi’r al-‘Arabī fī ‘Asharat Qurūn (1972) by Muṣṭafā Kāmil al-Shaybī. This significant work examines the rubā’ī (known as al-dūbayt in Arabic) from various perspectives and includes an appendix featuring around 900 quatrains composed by rubā’ī poets from the 5^th to the 14^th century AH. The author dedicates an independent section (pp. 58–72) to analyzing the meter of the rubā’ī, discussing the Persian rubā’ī meter (based on traditional Persian prosody manuals) and then the Arabic rubā’ī meter, favoring the well-known metrical pattern (fa’lun mutafā’ilun fa’ūlun fa’alun).
Seyr-e Robā’ī dar She’r-e Fārsī [The Evolution of Quatrain In Persian Poetry] (1995) by Sirous Shamissa is the second independent and detailed work on the rubā’ī, examining it from multiple angles and dedicating a separate chapter (pp. 245–278) to the prosody of the rubā’ī. Unlike al-Shaybī, who was not a prosody specialist and mostly followed other scholars' views on Arabic rubā’ī prosody, Shamissa is a prosody scholar himself and meticulously analyzes the historical and structural aspects of Persian rubā’ī meter. However, he focuses solely on Persian rubā’ī prosody, and no comparison between the two metrical systems is found in this book.
Finally, ‘Umar Khallūf authored an independent and valuable book titled Al-Baḥr al-Dubaytī (Al-Dūbayt): Dirāsa ʿArūḍiyya Taʾṣīliyya Jadīda (1997), which concentrates on the prosody of the rubā’ī (specifically the Arabic rubā’ī).
Other prosody books in Arabic and Persian have also briefly addressed the meter of the rubā’ī in passing. These opinions will be discussed and critically examined within the article.

Methodology

Given that the Arabic rubā’ī was influenced by the Persian rubā’ī, this research falls within the framework of comparative studies. The article adopts a comparative approach based on the French school of comparative literature, incorporating historical, analytical, and, in some cases, statistical methods. It should be noted that research in prosody (‘arūḍ) pertains to the formal and technical aspects of literature. Therefore, this study does not address the thematic content of rubā’īs In Persian and Arabic (such as their motifs or philosophical themes). Additionally, not all formal elements (such as rhyme [qāfiya] and refrain [radīf]) are within the scope of this paper. Instead, the focus is on the prosody of the rubā’ī, its metrical features In Persian and Arabic and the similarities and differences between the two traditions. In essence, this research belongs to the field of comparative prosody or, more precisely, comparative metrics (wazn-shināsī tatbīqī).

Discussion

This study begins by examining the names and origins of the rubā’ī In Persian and Arabic poetry. It then reviews the opinions of Arabic and Persian prosodists, from classical to contemporary scholars, regarding the metrical scansion of the rubā’ī. These views are critically analyzed in detail to determine the most suitable main meter for the rubā’ī in both languages. After establishing the main meter and its appropriate metrical scansion, the study explores the crucial topic of poetic license (ikhtiyārāt-e shā’irī) In Persian and Arabic rubā’īs. Numerous poetic examples are provided, accompanied by their metrical scansions and identified variations in meter. To quantify the frequency of these metrical variations in Arabic rubā’īs, a statistical analysis was conducted based on 150 Arabic rubā’īs. The results are presented in tabular form, alongside a comparison with the frequency of poetic license in Khayyam’s rubā’īs.

Conclusion

Although in traditional Persian prosody, other scansions have been proposed for the rubā’ī, based on modern Persian prosody, the appropriate scansion as the main meter of the rubā’ī is determined as mustaf’ilu mustaf’ilu mustaf’ilu fa’ (- - UU | - - UU | - - UU | -) (مستفعلُ مستفعلُ مستفعلُ فع).
On the other hand, while in Arabic prosody, the well-known scansion for the rubā’ī is "fa’lun mutafā’ilun fa’ūlun fa’alun" (- - | U U - U - | U - - | U U -) (فعْلن متفاعلن فعولن فعلن), and other scansions have also been mentioned, according to the author's view, the main meter is determined as mustaf’ilu maf’ūlātu mustaf’ilu fa’ (- - UU | - - - U | - - UU | -) (مستفعلُ مفعولاتُ مستفعلُ فع), with the only difference being in the second foot, where "maf’ūlātu" replaces "mustaf’ilu". This very difference has led to some variations in poetic licenses (ikhtiyārāt) in the Arabic rubā’ī compared to the Persian rubā’ī.
The type of poetic license in the Persian and Arabic rubā’ī is exactly the same in the position of the first foot of the hemistich, which is the option of taskīn (substituting a long syllable for two short ones) and replacing "maf’ūlun" with "mustaf’ilu", and in terms of frequency of use, this is nearly the same in both Persian and Arabic rubā’ī. The same applies to the position of the third foot of the hemistich.
As for the position of the second foot, both In Persian and Arabic, "mustaf’ilu" and "fā’ilātu" are used, and the use of "fā’ilātu" is much more frequent than "mustaf’ilu" in both systems. The key difference in this position is that in the Persian rubā’ī, "maf’ūlātu" is not used at all, whereas in Arabic, this foot has a notable usage (around 10%). For this reason, the foot ("maf’ūlātu") is considered the main one.