2,000-Year-Old Tefillin Cases Reveal Ground-breaking Secrets: Ariel University Research Redefines Historical Jewish Practices
18 June 2024
Ariel, Israel – Ariel University is proud to announce a ground-breaking study led by Professor Yonatan Adler, which provides new insights into ancient Jewish ritual artifacts known as tefillin. The paper, “Black surfaces on ancient leather tefillin cases and straps from the Judean Desert: Macroscopic, microscopic and spectroscopic analyses,” was recently published, in PLoS ONE. This collaborative effort includes Ilit Cohen-Ofri and Yonah Maor of the Israel Antiquities Authority, Theresa Emmerich Kamper of England’s University of Exeter, and Iddo Pinkas of the Weizmann Institute of Science.

Tefillin, essential to Jewish ritual practice, consists of leather cases and straps traditionally colored black. Professor Adler’s study meticulously examined seventeen ancient tefillin cases, some of which are over 2,000 years old, discovered among the Dead Sea Scrolls in the Judean Desert. These cases display very dark, nearly black surfaces. The research aimed to determine whether these cases were intentionally colored black using carbon-based or iron-gall-based pigments or if their coloration resulted from natural degradation processes. The comprehensive analysis employed a variety of advanced techniques, including:
- Macroscopic and Microscopic Analyses: Initial visual inspections and stereoscopic examinations of the leather surfaces.
- Multispectral Imaging: Used to identify the presence of carbon-based pigments through infrared wavelengths.
- Raman Spectroscopy: To detect amorphous carbon and other mineral molecules.
- Fourier Transform Infrared Spectroscopy (FTIR): To identify organic compounds and minerals.
- Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) Spectroscopy: To obtain high-magnification images and elemental compositions of the samples.
The results were revelatory. Contrary to initial hypotheses, no traces of carbon-based or iron-gall-based pigments were found. Instead, SEM analyses suggested that the black color observed on the surfaces of the tefillin cases was likely due to the natural degradation of the leather, specifically through a process known as gelatinization. This process, which results in the darkening of the leather, aligns with environmental exposure over centuries rather than intentional coloring.
Professor Yonatan Adler, an archaeologist at Ariel University, has dedicated his career to uncovering and understanding ancient Jewish practices. His expertise and meticulous research methods have brought significant advancements in the field of archaeology. “Our research offers a fascinating glimpse into the ritual practices of ancient Jewish communities,” said Professor Adler. “The absence of intentional blackening in these ancient tefillin cases suggests that the rabbinic prescriptions developed later were responding to earlier, more varied practices.”
Professor Adler’s study not only challenges preconceived notions about ancient Jewish rituals but also highlights the dynamic and evolving nature of these practices. The findings suggest that the practice of blackening tefillin, as prescribed in later rabbinic law, may not have been as universally applied in antiquity as previously thought. Instead, the Judean Desert tefillin likely represent a period before the rabbinic stipulation for black-colored tefillin was widely adopted.
The research was supported by the Israel Science Foundation, and the team expressed gratitude to the Israel Antiquities Authority and the Israel Museum for their invaluable assistance.