In addition, most Orthodox Jewish scholars reject any attempts to build the Temple before the coming of Messiah. This is because there are many doubts as to the exact location in which it is required to be built. For example, while measurements are given in cubits, there exists a controversy whether this unit of measurement equals approximately . Without exact knowledge of the size of a cubit, the altar could not be built. The Talmud recounts that the building of the Second Temple was only possible under the direct prophetic guidance of Haggai, Zechariah, and Malachi. Without valid prophetic revelation, it would be impossible to rebuild the Temple, even if the mosques no longer occupied its location.