מדרש על מדות 2:3

The narrative in Yechezkel³Yechezkel 40:6. mentions that the angel “ascended its steps.” In his commentary, Rashi refers to the mishnah in Middos,⁴Middos 2:3. which relates that there were twelve steps leading to the Women’s Courtyard. Each step was half a cubit high and half a cubit wide. Indeed, all of the steps in the Beis HaMikdash had these dimensions. The only exception was the steps leading to the Ulam. This is Rashi’s version of the mishnah. However, it seems that Rambam’s version of the text did not include the words “except the steps to the Ulam.”⁵See his commentary to the Mishnah.