Timber for the tabernacle… Today

(Midrashic and botanical evidence of the source of the lumber used in building the mishkan; December 2007; last revised September 2024)

In Exodus 26:15 (parshat Terumah), we read that the boards for the wall that surrounded the Mishkan (Tabernacle) were to be made from ”upright acacia trees” (in Hebrew, “atzei shitim omdim”). Acacia wood was also used to construct the Ark of the Covenant (Aron HaBrit). Two acacia species are common in the Sinai desert: The umbrella thorn acacia or Israeli babool (Vachellia tortilis), and the gum arabic tree or Indian babool (Vachellia nilotica). Under dry, desert conditions, these species grow as bushes or small, gnarled trees that would never be called upright. Note the slim, oblique branches of the umbrella thorn acacia shown here in a semi-arid grassland. In the harsher conditions of the Sinai desert, this species would be reduced to a small bush with short, tortuously twisted branches.

However, the boards described in Exodus are far larger than anything that could be cut from such a tree. The boards are to be 1 x 1.5 x 10 cubits in size. The cubit (Hebrew ‘amah’) is variously estimated as 18-24 inches. Thus, we find that the boards were at least 18 x 27 inches (45 x 68 cm) in cross-section, and 15 feet (nearly 5 m) long. The difficulty of obtaining such lumber in the desert was obvious to the Torah’s ancient readers, who were intimately familiar with the conditions of life in the various ecosystems of the Middle East. As is often the case, the Midrash (homiletical literature) provides an explanation. Variations and fragments of this midrash appears in at least three classical sources (Midrash Tanchuma Terumah 9; Bereishit Rabbah 94:4; and Yerushalmi Taanit 1:6). It describes a tradition that the patriarch Jacob recognized prophetically that his descendants would need these large timbers centuries later to build the Mishkan. He therefore directed his children to bring them along when they descended to Egypt. Jacob told them to take these trees from a place in the northern Jordan Valley called Migdal Tzava’ya (“The Dyers’ Tower”; the Talmud refers several times to this location as a center of cloth making and dying.). The midrash goes on to describe a tradition of refraining from cutting any of the acacias at Migdal Tzava’ya, out of respect for this grove as the source of lumber for building the Ark of the Covenant.

Several tantalizing lines of evidence offer support for this tradition. Today, Migdal Tzava’ya is located in northwestern Jordan. Remarkably, the local Arab population continues to regard the acacia trees of this site as sacred. But how could such large boards be cut from acacia trees? The acacias of Migdal Tzava’ya are of a different species from the desert acacias. In the moister climate of the Jordan valley, the white or winterthorn acacia (Faidherbia albida) provides a dramatic contrast to the desert acacia. The white acacia is an excellent candidate for the Torah’s term “upright acacia trees.” Its trunk is straight and tall, often reaching 98 feet (30 m) in height and 6.5 feet (2 m) in diameter, as seen here (JMK via Wikimedia Commons; license at https://creativecommons.org/licenses/by-sa/4.0).

The original grove at Migdal Tzava’ya has apparently spread since Talmudic times. F. albida can now be found on both sides of the Jordan river, in both Jordan and Israel. Today, visitors to the Galilee can view and contemplate trees that may be descendants of the same ones that Jacob collected to carry into exile in Egypt. In a novel echo of the protected grove of Migdal Tzava’ya, the winterthorn acacia is protected as an endangered species in Israel. In 1965, the government established the Shimron Nature Reserve, about 18 miles west of the Jordan River, to protect the winterthorn acacia grove there.

The midrashim are inconsistent on the question of whether Jacob’s family brought live saplings for transplanting or cut lumber from Migdal Tzava’ya to Goshen, in the Nile Delta. However, there is an isolated population of F. albida today in the western delta, which may be the remnant of an ancient grove of trees transplanted by our ancestors. Whether it was boards or live trees that were brought to Egypt, the midrashim suggest that their presence provided some consolation to the Israelites during their enslavement, as a reminder that this wood was prepared in advance for use after their promised liberation. In this vein, the late Lubavitcher Rebbe is said to have favored Midrash Tanchuma as the version of the midrash that he cited. This collection of midrashim is named for Rabbi Tanchuma bar Abba, the Talmudic sage to whom it is traditionally attributed. The Rebbe saw an allusion to this aspect of the midrash in the name Tanchuma, meaning consolation.

This pattern of consolation that precedes, and promises an end to misfortune appears in other midrashim as well. A better-known example is one that describes the shock that Rabbi Akiva gave his colleagues by laughing at the sight of a fox wandering the recently devastated Temple Mount. He explained that because the prophecy that the Temple would become a ruin inhabited by foxes had been fulfilled so quickly, surely its prophesied restoration would soon follow.

A puzzling detail in our midrash is an apparent indifference to the identity of these trees. The midrashim shift back and forth, at times seemingly at random, between the terms ‘shita’ (acacia) and ‘erez’ (cedar), as if the two were synonymous. Yet even the unfamiliar observer can easily distinguish these unrelated trees, which grow in very different environments. Certainly Rabbi Tanchuma, who lived in much closer proximity to nature than most of us do today, would have recognized this problem, if it really is a problem. One version of our midrash states that there are seven types of cedar, including acacia, maple, and several others that are not closely related to the cedar. Biblical metaphor often uses cedar as an example of a big, sturdy tree, so the midrash may simply be using it as a generic name for such trees, just as we refer to the “lead” in a pencil or the “burning” of body fat or nuclear fuel. But Talmudic classification of living things is a topic for another Torah Flora essay.