Each letter of the Hebrew alphabet is allocated a particular numerical value, depending on its position in the Hebrew alphabet. These days, Hebrew speakers use Arabic numerals (1, 2, 3, etc) when writing down numeric values, but in earlier times Hebrew letters were used for this purpose. Soon, an entire area of study called gematria arose, specialising in calculating the numeric values of words and comparing them to the numeric values of other words, and drawing conclusions about the interrelationships of the words as a consequence

Word-based numerology probably began in 8th century BCE Mesopotamia; Greeks practised isopsephia (letter-based calculation) from the 5th century BCE. Hebrew gematria only arrived in c.100 BCE, yet soon grew in complexity. Gematria is often used to detect the secret meaning of holy texts. Unsurprisingly, it became an indispensable tool of Jewish mystics (kabbalists) down the ages.

The numeration of the Hebrew alphabet spreads from 1 – 400 over its 22 letters, aleph א to tet ט, have values from 1 to 9; yud י to tzade,  10 to 90 (counting in tens); kuf, resh, shin and tav, 100, 200, 300 and 400 respectively. Then five final forms are added: final kaf equals 500, final mem is 600, final nun is 700, final peh equals 800, and final tzade is 900.

This 1 – 900 series, plus the subdivision of the 27-letter series into three enneads of nine sequential letters, is the same as the Greek alphabet. (Unlike Hebrew, Greek has 27 letters but no final forms). Hence some think Jewish gematria was modelled on Greek isopsephia. Even the position of a Hebrew letter in the alphabet can be significant. Take the letter tzade. Its numerical value is 90, but its ordinal position is 18. The gematric nomination for 18 is chet plus yud, which spells chai, or ‘life’. Going one step further, some kabbalists find meaning in the name of the letters themselves. Again, in tzade we find that the word itself totals 104. It echoes the similar word, tzadik, righteous person; and the name of the tzadik Isaac appears 104 times in the Tanach.

Genesis: 14 says that Abraham took 318 servants with him to battle. Commentators noted that the numerical value of the name of his servant Eliezer was 318. They thus deduced that Abraham in fact went into battle with Eliezer and no one else.

Jacob’s ladder (sulam) in Genesis 28: 12 has a numerical value of 130, the same as the value of the word Sinai. So scholars deduced that the law revealed to Moses on Mount Sinai is man’s means of reaching heaven.

Many Jews felt that gematria was being abused. Some called it a contrivance; others damned it as witchcraft. It certainly can waste time, as in the form of pilpul – sophistry connected with analysis of Talmudic passages. Especially controversial was the use of gematria to calculate when the Messiah would arrive. Of course, every Hebrew year is a number. Written as letters it forms a word, and some of these had portentous meanings.

Gematria is a popular area of study amongst those interested in Kabbalah (the mystical traditions of Judaism), but less attention is paid to it by other Jews who mainly regard it as an occasional entertaining diversion.

Jews still debate whether gematria is a brilliant tool of Talmudic exegesis or a silly superstition. What cannot be denied is that the skills gematria nurtured over the centuries: arithmetic dexterity and the ability to see patterns, formed a basis for a generation of Jewish scientists.