Tractate Middot is a detailed description of the Second Temple as built by Herod during the end of the first century B.C.E. The word “Middot” means “measurements” and it refers to the measurements of the Temple.
We should note that the sources of this description can be varied. Some of the sources are from the sages own memories or transmitted oral tradition. However, the memory of the Temple sometimes contains discrepancies and is sometimes brought in piecework. There are even occasional debates as to what exactly the Temple looked like. Occasionally, the rabbis use Ezekiel’s visions of the Temple in their own description, even though they were aware that the actual Temple did not look exactly as Ezekiel described it. On other occasions they even use descriptions of Solomon’s Temple, under the assumption that the First Temple served as guideline for the building of the Second Temple.
Josephus also offers up a detailed description of the Temple, and his description does not always accord with the rabbis’ description. We should also note that their reasons for describing the Temple were different. The rabbis described the Temple so that subsequent generations would rebuild it, speedily and in their time. Josephus described the Temple so that he could impress the Greeks. However, both the rabbis and Josephus agree that it was a most impressive building.
Middot has many similarities with Tamid, so we will make frequent reference to it as we learn these mishnayot. Both tractates are descriptive and differ distinctly from most of the other tractates we have learned.
Good luck in learning Middot!