Middot, Chapter Two, Mishnah Three
1) Within it was the Soreg, ten handbreadths high.
2) There were thirteen breaches in it, which had been originally made by the kings of Greece, and when they repaired them they enacted that thirteen prostrations should be made facing them.
3) Within this was the Hel, which was ten cubits [broad].
4) There were twelve steps there.
a) The height of each step was half a cubit and its tread was half a cubit.
5) All the steps in the Temple were half a cubit high with a tread of half a cubit, except those of the Porch.
6) All the doorways in the Temple were twenty cubits high and ten cubits broad except those of the Porch.
7) All the doorways there had doors in them except those of the Porch.
8) All the gates there had lintels except that of Taddi which had two stones inclined to one another.
9) All the original gates were changed for gates of gold except the gates of Nicanor, because a miracle happened with them.
a) Some say: because their copper gleamed like gold.
Section one: Around the Temple there was a small partition called the Soreg. This set the Temple off from the rest of the Temple Mount.
Section two: The Greeks made thirteen breaches in the Soreg in order to demonstrate that Gentiles could enter the Hel, which was inside the Soreg. This tradition is also reflected in I Maccabees 9:54: In the year one hundred and fifty-three, in the second month, Alcimus ordered the wall of the inner court of the porch to be torn down, thus destroying the work of the prophets.
When the Hasmoneans expelled the Greeks, they repaired the breaches and enacted that anytime a person would pass one of them, he would bow down and thank God for their victory over the Greeks.
Section three: Within the Soreg was an area called the Hel. This was an empty area ten cubits (about five meters) wide.
Section four: Leading up from the Hel to the Temple courtyard were twelve steps. Each step was half a cubit high and half a cubit long.
Section five: The only steps in the Temple that did not have this dimension were those that led up from the courtyard of the priests to the Porch, whose length varied as we shall see in 3:6.
Section six: The mishnah now proceeds to note several differences between the dimensions of the Porch and the dimensions found elsewhere in the Temple. The gates of the Porch were forty amot high and twenty amot wide.
Section seven: The entrance to the Porch was set off with a curtain and not a door.
Section nine: Originally the gates were made of copper. When the Jews had more money, they refurnished the Temple and covered them with gold. The only exception was the Nicanor gates, which were not changed. There are two possibilities for why they stayed the same. First of all, there was a miracle performed with them. This is explained in the Bavli (Yoma 38a) in the following way: What miracles happened to his doors? They say that when Nicanor had gone to bring doors from Alexandria of Egypt, on his return a storm arose in the sea to drown him. They took one of his doors and cast it into the sea and yet the sea would not stop its rage. They wanted to cast the other into the sea. He rose and clung to it, saying: Cast me in with it! The sea immediately stopped its raging. He was deeply grieved about the other [door]. When he arrived at the harbor of Acco, it broke through and came up from under the sides of the boat. Others say: A monster of the sea swallowed it and spat it out on the dry land.
The other explanation is that there was no need to replace the gates of Nicanor because their copper shined liked gold.