A groundbreaking archaeological find by the Israel Antiquities Authority (IAA) in the caves of the Judean Desert has kicked up a storm of controversy by questioning a long-held tradition surrounding one of Judaism’s most sacred rituals.

Tefillin are small leather boxes containing sacred Torah verses that Jewish men don daily during morning prayers, secured to the head and arm. Jewish law has mandated that Tefillin be dyed a distinctive jet black.

However, analysis of 2,000-year-old tefillin cases discovered this month near Qumran, where the Dead Sea Scrolls were famously unearthed in 1949, has challenged this tradition. Using multispectral imaging and Raman spectroscopy, the IAA ruled out any presence of artificial black dyes or pigments on the ancient tefillin cases.

“In ancient times, there were two main methods for dyeing leather black. The first method used carbon-based materials to give the leather a black color. The second method was based on a chemical reaction between tannin, a complex organic compound found in many plants, and iron oxides,” IAA Director Dr. Ilit Cohen-Ofri said in a statement.

“In our tests, we ruled out the possibility that the tefillin cases were dyed black using either of these methods.

Contemporary rabbinical leaders must now carefully consider if the centuries-old tradition of dyeing Tefillin black should remain unbreakable, with the archaeological discoveries merely reaffirming Judaism’s ever-living nature.