Study: Ancient phylacteries’ natural leather color illustrates evolution of Jewish law
Analysis of 2,000-year-old tefillin found in Judean Desert caves shows no dye was used in their construction; deep black is mandated by contemporary Jewish Law
Gavriel Fiske is a reporter at The Times of Israel
The phylacteries Jews used in the Holy Land over 2,000 years ago were probably the color of their natural leather, not dyed black as mandated by Jewish Law today, according to a PLOS ONE study released Thursday.
“This is a very important discovery,” said Prof. Yonatan Adler of Ariel University, who led the study. “This is the first time that tefillin have been scientifically examined to determine their color.”
Phylacteries, or tefillin, are small leather boxes containing scriptural verses that observant Jewish men (and sometimes women) affix to their heads and upper arms with leather straps as part of morning prayers. The construction of tefillin is bound by minute details of halacha (Jewish Law), including the universal black color used today.
An Israeli-British study examined a group of 2,000-year-old tefillin cases found in the desert caves at Qumran, where the Dead Sea Scrolls were discovered, and determined that no dye at all was used in their construction, meaning they would have had their natural leather color.
According to a discussion in the Gemara, a foundational Jewish legal text redacted and compiled circa 500 CE, the straps of the tefillin were required to be black, but there was a debate over whether the boxes themselves were also obligated to be black under this ruling.
While the practice of dyeing the straps and boxes likely predated the rabbinic ruling, this study aids in pinpointing when it may — or may not — have become widespread.
The study, “Black surfaces on ancient leather tefillin cases and straps from the Judean Desert: Macroscopic, microscopic and spectroscopic analyses,” was released Thursday in the peer-reviewed journal PLOS ONE. The study was conducted by researchers from Ariel University, the Israel Antiquities Authority, the University of Exeter (UK) and the Weizmann Institute of Science.
Some of the ancient tefillin have “a natural brown color,” but others have a very dark shade that was “previously thought to be the result of artificial dyeing done to comply with the law that requires the leather of tefillin cases to be black,” Adler said.
“Our tests have shown that where the leather appears dark, it is the result of a natural process and not intentional dyeing,” he said.
In examining the ancient phylacteries, the researchers used a series of modern methodologies, including multispectral imaging, Raman spectroscopy (a non-destructive chemical analysis technique), ATR-FTIR spectroscopy and SEM/EDX (scanning electron microscopy with energy dispersive X-ray spectroscopy).
“The results of the analyses showed no evidence of black colorants on any of the tefillin cases,” the researchers wrote in an IAA press release announcing the findings.
“In the dark fragments we examined, the color appears to be the result of natural leather aging rather than intentional dyeing… In the past, we have found that some of the Dead Sea Scrolls have also undergone a similar process, which unfortunately has caused the parchment to darken,” explained Dr. Yonah Maor of the Israel Antiquities Authority’s analytical laboratory.
The tefillin used in the study were discovered in 1949 near Qumran, and additional cases were later found in other nearby caves in the Judean Desert. Significantly smaller than most modern sets of tefillin, all date from the end of the Second Temple period, or around 2,000 years ago, and the desert climate enabled the phylacteries to remain relatively unscathed.
They are currently housed in the IAA’s Dead Sea Scrolls Unit in Jerusalem, which replicates the conditions of the desert caves.
Due to the findings, it’s likely that the practice of coloring tefillin cases a dark black color was “a later tradition” which “may not have been in place in the Second Temple period when the ancient tefillin examined in the study were in use,” the researchers noted.
“It is likely that in the beginning, there was no halachic significance to the color of tefillin,” Adler said. “Only at a later period did the rabbis rule that tefillin should be colored black.”
Even after black tefillin became the norm, “halachic authorities continued to debate whether the requirement to color tefillin cases black was an absolute obligation or merely preferable for aesthetic reasons,” Adler said.
“It is commonly thought that Jewish law is static and does not develop. Our ongoing research on ancient tefillin shows that the exact opposite is true; Jewish law has always been dynamic. In my view, it is this vibrancy that makes halachah so beautiful,” said Adler.
