Understandably, the most valuable metal available – gold – was used in making the Ark of the Covenant – “And you shall overlay it with pure gold” (Ex. 25:11). But if the gold was outside the ark, what was inside?
From the previous verse we learn that the answer was wood. Wood inside and gold outside – why was the Ark not made completely of gold? Surely gold is more precious and more durable than wood! Surely the word of God deserves a completely golden repository, since the Psalmist says it is even more precious than gold (Psalm 19:11) and the Book of Proverbs says (16:16) that it is better to get wisdom than gold. What could the Almighty have been thinking of when He commanded the use of wood?
A fascinating problem, but maybe the answer is that gold and wood each has a special quality. God wanted the gold to symbolise preciousness and permanence, but He wanted the wood to suggest the living nature of the Torah and its life-giving quality. The Torah is etz chayyim, a tree of life (Prov. 3:18). A tree is not inanimate like gold; it is a living thing, and not only does it have life but its branches give shelter and its fruit gives nourishment.
If the only casing the Torah had were gold, we might value it, cherish it and revere it, but we might not utilise it for daily inspiration and guidance.