The all-time Gematriya master was without a doubt, Rabbi Yaakov ben Asher (1269-1343), from Germany and then Spain. We know how good he was at Gematriyos by reading his brief commentary on the Chumash. This commentary is a treasure chest of hidden Gematriya secrets. It was called Ba’al HaTurim, meaning the “Master of the Four Rows.”
What’s that name all about?
Besides his Chumash commentary, Rabbi Yaakov’s most lasting gift to Torah learning was a large collection of four books, called the Arba’ah Turim, “Four Rows,” named for the four rows of jewels in the breastplate of the Kohen Gadol. This important work, also called in short, the Tur, is an invaluable link in the chain of Jewish law.
Through carefully learning the teachings of the Sages who came before him, especially those of the Rambam, Rabbi Yitzchak Alfasi (a.k.a. the Rif), and the Rosh (his father), he wrote a thorough guide to Jewish life.
Arba’ah Turim is divided into four sections:
Orach Chayim deals with the “ordinary” laws that come up in everyday life, including laws of prayer, Shabbos, the holidays and more.
Yoreh Deiah includes the laws of Kosher.
Even HaEzer is the place where all laws related to Jewish marriage can be found.
Choshen Mishpat contains the laws dealing with business, damages, and monetary issues.
This book was so important to Jewish life that it was the second Torah book to be printed (in the year 1475, just 35 years after the printing press was invented) and has since been reprinted countless times. In fact, when the Shulchan Aruch (Code of Jewish Law) was written, it was organized following the same format of the Arba’ah Turim.
So, when Rabbi Yaakov wrote his Gematryia commentary on the Chumash, there were those who looked at it, and after a quick glance would close the book, thinking, “I would rather spend my time learning “real Torah,” and not waste my time on this Gematriya handbook.”
That explains why it was called Ba’al HaTurim. It’s as if to say, “Watch out! Do you know who wrote that book?! It’s none other than the same author as the Arba’ah Turim, the classic book of Jewish law! So, it must be something special and very holy!”
Indeed, Ba’al HaTurim on the Chumash became so popular that after all these years, it is still printed in most editions of the Chumash, right alongside the classic words of Rashi!