This is what is meant by the teaching that “the Name HaVaYaH does not change in any place in its four letters...” (Tikkuney Zohar #57, 94b). What this means is that this Name, made up of its four interconnected letters, is only mentioned when the Cause of causes unifies all the different levels in the mystery of His unity. The Name of HaVaYaH “does not change” in the sense that the Name of HaVaYaH controls all the different levels in order to bring them into unity and to show that despite their various differences, they all serve only one purpose. This is to demonstrate His unity through the fact that He brings everything back to good.