My Response: “Let there be a firmament” means that there should be a clear division between those who take you away from the Creator and those who help you. You must determine who is helping and who is not and even turn your enemies seemingly into helpers in this movement toward Him.
As a result, the “firmament” should become the border through which you constantly reallocate everything that you have in this world to Him, everything that is in you and in others. You attribute everything to Him!
Question: And later, will the firmament be no longer needed?
Answer: Yes. It descends to the level of our Earth and everything becomes one single heaven. From the point of view of Kabbalah, this is Tzimtzum Bet (Second Restriction), the ascent of Malchut to Bina and their connection with each other.
From KabTV’s “The Power of The Book of Zohar” #10