שמות, פרק כ״ח, פסוק ט״ז

The breastplate of the High Priest was a masterpiece of careful design, transforming a simple piece of woven fabric into a sacred vessel of divine communication. Its creation required precise craftsmanship to form a garment that was both physically sturdy and spiritually profound.

The foundational measurement for this garment was the span, defined as the distance between the tip of the thumb and the tip of the pinky finger when the hand is stretched wide open [הכתב והקבלה, ביאור שטיינזלץ]. This distance equals half a cubit, or slightly more than twenty centimeters [רשב״ם, ביאור יש״ר, ביאור שטיינזלץ]. While there is some discussion regarding whether a span might be considered a third of a cubit if measured in a straight line through the air, the measurement of half a cubit is achieved by measuring along the curve of the stretched fingers [הכתב והקבלה, פרדס יוסף].

The primary approach among commentators is that the fabric was originally woven as a rectangle, measuring two spans in length and one span in width. It was only after this rectangular cloth was folded in half that it formed a perfect square measuring one span by one span [מלבי״ם, משכיל לדוד, ביאור יש״ר, רש ר הירש, קאסוטו]. The design specifically emphasizes the square shape to highlight that this final form was achieved strictly through the act of folding, rather than being woven that way initially [העמק דבר].

This folding served several vital purposes. Most notably, it created a pocket or inner hollow, likely with the crease resting at the bottom [ברכת אשר על התורה]. Inside this hidden space rested the Urim and Thummim [רשב״ם, שד״ל, ביאור שטיינזלץ, קאסוטו], which consisted of the explicit, holy name of God [הדר זקנים, ברכת אשר על התורה]. Through these sacred elements, the priest could resolve uncertainties, receive divine guidance through the holy spirit, and even determine the exact territorial borders of the tribes [אבן עזרא הקצר, דעת זקנים].

Beyond its spiritual function, the folded design provided essential physical reinforcement. The garment consisted of two distinct layers. The front layer carried the heavy precious stones and their metal settings, while the back layer acted as a sturdy lining. This double thickness ensured that the weight of the gems would not tear or damage the fabric [הדר זקנים, דעת זקנים]. Furthermore, this folded structure allowed the breastplate to be worn properly. Suspended from the shoulder straps of the ephod behind it, the folded breastplate draped slightly forward, resting securely and stably upon the heart of the priest [רש״י, הדר זקנים].