When we read about the various fixtures, we are more likely to imagine pictures than think of numbers. That is with one notable exception, and that is the menorah. While all of the vessels can correctly be described by their measurements or by having four corners, etc., the menorah is the only one the very essence of which is numerical. That is, it is immediately visualized as being composed of its seven sub-divisions, or branches.
As pointed out by Ramban (on Bereshit 2:3,6) and others, seven is possibly the most significant number in Jewish Thought. Being the number of all sorts of observances, he tells us, is only the visible manifestation of its great mystical significance. That the days of creation are seven is therefore no coincidence and only the beginning of all sorts of things that would follow this pattern.
There are certainly many facets to this number, most of which relate specifically to the number seven and nothing else. However, it may be not be insignificant that the number seven also belongs to the larger set of odd numbers. Something being odd or even is not the type of thing that most of us have thought much about. But perhaps it should be.
That there is an important difference between odd and even numbers is something that was held to be true by many ancient cultures and noted by several great thinkers. This includes the most famous mathematician, Pythagoras. But Pythagoras was not only a mathematician. As reported by Aristotle and others, he was a great philosopher who saw numbers as a central avenue through which to understand existence more generally. As such, he had very set opinions about the difference between even and odd. For him, the odd embodied form and the good, whereas the even embodied matter in its chaotic state (though he was also particularly fond of the number, ten, in spite of its being even).
I believe that much of what Pythagoras explained about the nature of odd numbers in words, the menorah explained even more powerfully with an image. For while the candles are indeed described as seven, the Torah only speaks about six branches – the seventh being described as the menorah itself, meaning its core. Hence the middle branch is not really akin to the branches of a tree – as are the other six – but rather to its trunk. And one unit sticking out in the middle of symmetrical pairs can be seen as the essence of odd numbers.
But it is not just a question of one unit in the group being different than the others. Though the middle position of the disparate unit prevents if from being paired up, it also gives it a relationship to the others around it. If we look at the menorah, we see that the middle branch is not only longer than all of the other branches, it is the only one that reaches the floor. As a result, all of the other branches are suspended from – and so completely dependent on – it. That is to say that without the middle branch, all of the other branches would simply fall uselessly to the floor.
That image – as R. S. R. Hirsch also picks up – is a replica of our relationship with God. While He allows us to have our own existence, as manifested by the other lights, that existence is impossible without Him. What the menorah shows so tangibly is that cognizance of God is manifested specifically in the odd. Properly understood, it helps us in the realization that whatever exists has another superior Element to it – One that is present in everything and yet of a totally different nature.
And with that we realize the power of odd numbers. In the odd we are subliminally reminded of God. It is presumably this type of subliminal clue that made the Temple such an inspiring place.
Unfortunately, we have no Temple today. But if we lack the spatial oddness of the menorah, we at least have the temporal oddness of the week (and shmittah, the holidays, etc.). Just like the central branch of the menorah, the central day of the week, Shabbat, is what holds up the rest of it. For without the Shabbat to refrain from work and focus on the spiritual, the other days simply fall emptily to the ground.
Reflecting on the purposely odd structure of the week can help us understand that Jewish time is structured in such a way as to also remind us of God and our relationship with Him. But be it in time or space, the subliminal messages are there. All that is needed is for us to allow them to penetrate.