At the end of the parsha in 20:22-23 we have two interesting lessons learned directly from the construction of the mizbeiah:
- Stones do not hear, see or have feelings, yet the Torah says not to use metal in hewing the stones for the mizbeiah because metal is the source of strife and disharmony (weapons for war), so how much more so someone who actually effects peace between different people will avoid tribulations.
- These stones have no concerns, yet the Torah says not to make steps so as not to shame the stones with the (semi-)nakedness of the Kohen, how much more so one should be careful not to shame a person who does have feelings and concerns and is created in the image of Hashem.
It is interesting that we learn such direct lessons from the construction of the stones for the mizbeiah. The various other parts of the mishkan all teach us things by their representation (e.g. table represents wealth, candelabrum represents wisdom, etc..). Yet only here do we see a specific lesson being directly taught.
I think the mizbeiah is representative of our relationship with Hashem. It is the focal point of our relationship. That is where we directly relate and interact with Hashem.
The place that is such a focal point needs to be constructed at such a level of complete purity. Our relationship with Hashem is dependant on our relationship with our fellow man. If we do not treat our fellow man with the respect he deserves, we will never be able to fully develop the relationship with Hashem.
Because the mizebiah is the focal point of our relationship with Hashem, that is why it directly tells us these important lessons, so that we will be able to develop our relationship with Hashem by first perfecting our relationship with man