שמות, פרק כ״ו, פסוק כ״ח

The structural stability of the Tabernacle relied on a unique central element designed to bind the separate wooden boards into a single, solid structure. Its primary function was to connect and pass completely from one side to the other, firmly securing the walls [אבן עזרא]. Out of the five horizontal bars supporting each wall, this served as the middle one [קאסוטו, ביאור שטיינזלץ, רש ר הירש].

The primary approach among commentators is that this central bar was completely hidden from view. While the other four bars rested in gold rings outside the boards, the middle bar was threaded directly through holes drilled into the very thickness of the wood itself [העמק דבר, רש ר הירש, ביאור שטיינזלץ, בכור שור, חזקוני]. However, an alternative perspective suggests that none of the bars passed through the wood; instead, they were all held by rings on the inner surface of the Tabernacle walls [קאסוטו].

Unlike the upper and lower bars, which were constructed in halves that met in the center of a wall, the middle bar was a single continuous piece that spanned the entire length from end to end [רבנו בחיי, ביאור שטיינזלץ, בכור שור]. Regarding its total span, there is a deep difference of opinion. The straightforward understanding is that each of the three walls had its own independent, straight middle bar [העמק דבר, תורה תמימה, בכור שור]. In contrast, a prominent tradition describes a miraculous phenomenon: there were not three separate bars, but rather one single middle bar that wrapped around the north, west, and south walls of the Tabernacle. According to this view, the wood would miraculously bend at the corners, reaching a total length of seventy cubits [רבנו בחיי, תורה תמימה, רש ר הירש].

Conceptually, this internal, embracing bar symbolizes peace and unity within the people of Israel. It represents the quiet force that binds everyone together into a single vessel capable of holding the abundant blessing of God [פרדס יוסף, רש ר הירש]. Tradition links this unifying inner strength to the patriarch Jacob, whose character brings harmony to opposing extremes. It is told that Jacob actually brought this specific piece of wood down with him to Egypt. He commanded his sons to take it with them when they were finally redeemed, ensuring it would serve as the unifying core of the Tabernacle [רבנו בחיי].