Also see the article on numerical miracle of the Qur’an.
First of the eight groups into which the Arabic letters are divided following a certain numerical value given to each of the consonants from pre-Islamic times, with the words themselves carrying no meaning. They are arranged in the following manner,
alif = 1, baa = 2, jeem = 3, daal = 4, haa = 5, waaw = 6, zaa = 7, haa = 8, taa = 9, yaa = 10, kaaf = 20, laam = 30, meem = 40, noon = 50, seen = 60, `ayn = 70, faa = 80, saad = 90, qaaf = 100, raa = 200, sheen = 300, taa = 400, thaa = 500, khaa = 600, dhall = 700, daa = 800, zaa = 900 and ghayn = 1000.
For example, following the above system, the total numerical value of the basmalah
works out to 786. Or a name like (Naseem Akhtar) will yield the date of birth in Hijri system as 1361. Obviously, this was a brilliant technique for preserving dates at a time when there were no calendars. In Urdu, poetical pieces composed at the death of a person ingeniously used letters, while keeping the rhyme and rhythm, yield the year of birth, death or both.
The following report from Alusi’s Tafsir work Ruh al-Ma`ani demonstrates the importance the Jew attached to the system (to them Gematric values), taking it to such foolish extremes, but which hold no importance in Islam except when employed for purposes indicated above to which we may add that it could be skillfully used the other way round, to yield secret messages.
Huyyi ibn Ukhtab, a Jew, came to the Prophet (saws) and said: “Is it true that it has been revealed to you, `Alif. Lam. Mim. This Book ...” (Al Baqarah, verses 1 2)? The Prophet said, “Yes.” Huyyi said, “We do not know of any prophet before you who was told about how long he and his followers would last. You seem to be the exception, for (according to the classical numbering of letters) alif is equal to 1, lam to 30, and mim to 40. The total works out to 71. (This is the period that your religion will last). Do you have more of them?”
The Prophet (saws) replied, “Yes, Alif. Lam. Mim. Sad.” Huyyi said: “That makes it 161 years. Is there more to it?” The Prophet (saws) said, “Yes, Alif. Lam. Ra” (which add up to 231). Huyyi said, “That makes it a bit longer. However, is there any more?” The Prophet said, “Yes, Alif. Lam. Mim. Ra.” (These add up to 271, and the grand total works out to 734) Huyyi said: “Surely, this is longer and more burdensome (to bear).” Then he turned to his companions and said, “Let’s go. The affair is a bit confusing.”