The Arabic abjad: letters, numbers and chronograms in verse

The word abjad brings together the first four letters of the ancient Semitic order: alif, ba, jim and dal. In Arabic it denotes both that order and the system that assigns a numerical value to each of the twenty-eight letters, from units to tens and hundreds, up to ghayn, which is worth a thousand. The logic is the same as in the Hebrew and Greek systems, inherited from the alphabets of the Aramaic sphere and adapted to the letters that Arabic had added.

An order older than the alphabet

The Arabic alphabetical order in use today groups letters by similarity of shape, but the abjad preserves the original Semitic sequence. To remember it, eight conventional words were used, abjad, hawwaz, hutti, kalaman, sa'fas, qarashat, thakhadh and dazagh, which have no meaning of their own. In the Maghreb and Islamic Spain a variant circulated with some letters arranged differently, and therefore with partly different values.

Before the spread of numerals of Indian origin, the abjad was also used to write numbers in documents, astronomical tables and treatises. Arab and Persian astronomers went on using it for a long time in their tables, because letters took up little space and were immediately legible to specialists. Even today the letters of the abjad are sometimes used to number paragraphs, pages and appendices, much as we use a, b and c.

Chronograms in Persian and Ottoman poetry

Its most refined use was the chronogram, called tarikh. The poet composed a final line whose letters, added together, gave the year of the event being celebrated according to the Hijri calendar: a birth, a death, the building of a mosque or a fountain. Often an introductory phrase warned the reader that the following line contained the date, inviting him to do the sum.

In Ottoman epigraphy such lines are common above doors, fountains and tombs, and the tradition also flourished in Persia and Mughal India. Being able to build an elegant chronogram, in which literal meaning and numerical sum coincided without strain, was considered proof of great poetic skill. The genre required a double competence, literary and arithmetical, and became one of the favourite pastimes of court men of letters.

The science of letters

Alongside practical use there developed the so-called ilm al-huruf, the “science of letters”, which attributed symbolic and cosmological properties to the letters and their numbers. The best-known text of this current is the Shams al-ma'arif, traditionally attributed to Ahmad al-Buni, who lived between the twelfth and thirteenth centuries, although the form of the work known today is the result of later additions. Many jurists and theologians regarded these speculations with suspicion.

A popular echo of the abjad is the number 786, widespread above all in South Asia. It corresponds to the sum of the letters of the formula bismillah al-rahman al-rahim, “in the name of God, the Gracious, the Merciful”, and is sometimes written at the head of letters and documents in place of the formula itself, so as not to expose the sacred text to profane use.

The abjad thus runs through very different registers: accounting, astronomy, court poetry, devotion and esoteric speculation. Knowing it helps in reading inscriptions and manuscripts of the Islamic world, where a date may be hidden in a line of verse and a number may take the place of a prayer. For the historian, moreover, chronograms are often a valuable source of dating when other documents are lacking.