שמות, פרק כ״ו, פסוק כ״ט

The walls of the Tabernacle were designed to achieve both structural stability and absolute visual perfection, ensuring that every visible detail was either crafted from or covered in gold [קאסוטו]. The wooden boards that formed the structure were completely encased in gold on every side. This comprehensive covering extended even to their inner thickness, which remained entirely hidden from the outside eye [מלבי״ם].

To hold these boards securely together, gold rings were attached to them to serve as brackets [רש״י, שטיינזלץ, נתינה לגר]. Connecting wooden bars were then threaded through these rings. This entire support system of rings and bars protruded exclusively from the exterior side of the Tabernacle, leaving the interior walls perfectly smooth and unbroken [רש״י]. However, the central connecting bar functioned differently. Instead of passing through external rings, it ran directly through a hollow space carved into the middle of the boards themselves [ספורנו].

The primary approach among commentators is that the connecting bars were not directly wrapped or glued with gold. Instead, hollow, semi-circular golden tubes were mounted onto the exterior of the boards, spanning the spaces between the rings. When an outer bar was threaded through a ring and slid into these tubes, it became fully enclosed in gold once it rested in its final position [רש״י, שד״ל, הדר זקנים, שפתי חכמים].

This unique method was chosen to maintain strict uniformity among all the bars. Because the central bar traveled through the interior of the boards and did not receive a direct layer of gold, the outer bars were treated in the exact same manner. They gained their golden appearance only by entering their prepared golden sleeves [משכיל לדוד]. To complete this uniform system, dedicated golden tubes were also inserted into the hollow interior of the boards, allowing the central bar to pass through a continuous golden tunnel from one end to the other [ביאור יש״ר, מלבי״ם].