G-d wants the Jewish People to build a Tabernacle (Mishkan) to house His Divine Presence and He commands them to donate the raw materials from which the Mishkan and its utensils will be fashioned [Shemot 25:3-7]: “Gold, silver, and copper; blue, purple, and crimson yarns… lapis lazuli and other stones for setting, for the ephod and for the breast-piece.” The Mishkan should be grand. It should be opulent. It should inspire unalloyed awe.
The Ben Ish Chai, writing in “Aderet Eliyahu”, asks why the Jewish People needed to donate any material other than gold. If gold is the most valuable metal on earth, why not build the entire build the entire Mishkan out of gold? Obviously, where it was unfeasible to use gold, such as in the walls of the Mishkan, other materials were used, but where metal was used, why not use exclusively gold? The Talmud in Tractate Zevachim [98a] teaches that “There is no room for poverty where there is wealth”, meaning that in financial matters concerning the Mishkan or, later on, the Holy Temple (Beit HaMikdash), we need not concern ourselves with identifying the least expensive solution. So why bother with copper or silver? Two immediate answers come to mind:  That’s what G-d wanted and who are we to attempt to understand and  Gold is more beautiful when it is offset by copper and silver. It is impossible to argue with either of these answers so we will set them aside for the time being. A more utilitarian answer could be that while gold is a beautiful and valuable material, it is very heavy and soft. Using gold for the entire Mishkan would have made it difficult to transport and maintain. By using a variety of materials, the Mishkan would be more portable and durable. The Ben Ish Chai proposes a more prosaic answer, suggesting that that the importance of the Jewish People donating to the Mishkan was not what was being donated, but, rather, how the donation was made. It was critical that each person’s donation be made cheerfully – every Jew had to be a willing participant in the building of an abode for G-d. Because not everyone can donate gold with a smile on his face, G-d allowed the more miserly people to donate less expensive materials such as copper and silver, as long as they donated them wholeheartedly.
Let’s zoom out and ask a different question: The Mishkan was constructed three and a half thousand years ago. According to our Sages in the Midrash [Tanna d’Vei Eliyahu Rabbah 25] the Mishkan was buried after the Beit HaMidkash was built. There will never be another Mishkan. What can we in the twenty-first century learn from the construction of the Mishkan that we can implement in our daily lives? Rabbi Samson Rafael Hirsch discusses the symbolism of the materials used in the construction of the Mishkan: “Metals in general, in accordance with their physical property of hardness, are used as a metaphor for firmness and strength, and in accordance with their being valuable, as a metaphor for valuing spiritual values, especially in accordance with their metallurgical properties as the most suitable metaphor for all goodness and truth.
Whereas copper represents an ignoble nature, one not yet refined; silver describes the stage of still requiring purification but of being able and fit to be refined; gold, which is usually found pure, and unmixed, and also resists the strongest tests, is the picture of the purest, most sterling, moral nobility and of true, real permanence and constancy.
Metals combine the highest degree of adaptiveness with the highest degree of firmness and stability; under heat and hammer, they can be adapted to any desired form, but once they have received that form, they retain it with a persistence that can only be destroyed by violence. They represent by these properties those very characteristics that we should have towards our duty in general, and especially towards the will of G-d, as revealed to us by His word”. The use of a variety of materials in the construction of the Mishkan served to symbolize the diverse aspects of the our relationship with G-d. Each material used in the Mishkan had a specific meaning and represented a different aspect of faith and worship. Consequently, the combination of different materials served to enhance the religious significance of the Mishkan, rather than to detract from it.
Let us attempt to add another layer to Rabbi Hirsch’s answer, gold, silver, and copper are all metals. They all possess “the highest degree of firmness and stability”. And yet pure gold is the most prevalent metal in the Mishkan. What does gold provide that silver and copper do not? I would like to suggest a slightly different route. The price of gold today is about $1842, nearly ninety times more expensive than silver and seven thousand times more expensive than copper. Why is gold so much more expensive? Gold is not particularly useful. While it is used extensively in the electronics industry in electrical connectors, more than fifty percent of the world’s gold is used in jewelry. Clearly, gold is aesthetically pleasing, but many people, myself included, find silver even more aesthetically pleasing than gold. The Talmud in Tractate Beva Metzia [84a] admits as much when it describes the beauty of the sage, Rabbi Yohanan: “To see something resembling the beauty of Rabbi Yohanan one should bring a new, shiny silver goblet and fill it with red pomegranate seeds and red roses, and position it between the sunlight and shade. That luster is a semblance of Rabbi Yohanan’s beauty.” The reason gold is so expensive is because it is so rare. It is estimated that just over 200,000 tons of gold have been mined over the course of history, the bulk of which has been in the last seventy years. As supply and demand determine the market price of a commodity, the more rare a commodity is, the more it costs. There is about eight times as much silver in the world today as there is gold, hence the price difference. Does this make gold any more special than silver and copper? Again, what can we learn from the abundance of gold in the Mishkan?
Gold, silver and copper have similar physical properties. Their hardness, melting point, and thermal conductivity differ by only about twenty percent. Nevertheless, there is one property in which gold stands out and that is in “yield strength”. According to Industrialphysics.com, “Yield strength is the point… where elastic behavior ends, and plastic behavior begins. If a sample is being tested and the yield point has not been reached, the sample will return to its original shape once the force being applied ends. However, once the yield point has been passed the sample will become permanently deformed.” Rabbi Hirsch correctly noted that all metals can be bent and that after being bent, they will retain their new form. This is true only if the metal is bent using a certain force – the yield point. If the force used to bend the metal is less than this force, then the metal will revert – snap back – to its original form. The yield strength of gold is five times the yield strength of silver and five times the yield strength of silver. What is the connection between yield strength and the Mishkan? While the commentators disagree as to whether the Mishkan was built prior to or subsequent to the sin of the Golden Calf (egel), the proximity of the Mishkan to the incident of the egel, coupled with the extensive use of gold in both instances, serves to inextricably link the two. When the Jewish People sinned at the egel, there was fear that their connection to G-d had been forever severed – it had been “destroyed by violence”. The gold in the Mishkan symbolizes a person’s ability not to be defined by his sin, but to be able, with the proper repentance, to learn from it and to revert back to the person he was before he sinned. The Mishkan not only inspires unalloyed awe, it inspires the alloyed soul to return to its original purity.
Ari Sacher, Moreshet, 5783
Please daven for a Refu’a Shelema for Yechiel ben Shprintza, Geisha bat Sara, Hila bat Miriam, Avraham Menashe ben Chana Bracha, Batya Sarah bat Hinda Leah and Rina bat Hassida.
 The Hebrew “nechoshet” is translated both as “copper” and as “brass”, an alloy made of copper and zinc.
 Rabbi Yossef Haim of Baghdad, known as the “Ben Ish Chai”, lived in the second half of the nineteenth century.
 The boards of the Mishkan were made of acacia wood and plated with gold. Gold weighs about ten times as much as wood such that had the boards been made entirely of gold, they would have been nearly impossible to transport in the desert.
 This answer was proposed by myself but paraphrased by ChatGPT. Scary.
 Rabbi Samson Rafael Hirsch, lived in Frankfurt am Mein in the nineteenth century.
 My iPhone contains 0.034 grams of gold
 The yield strength of Kevlar, the material of which many bullet-proof vests are made, is nearly twenty times the yield strength of gold.