Just curious, do you know what a metaphor is? Metaphor: A figure of speech in which a word or phrase that ordinarily designates one thing is used to designate another, thus making an implicit comparison, as in “a sea of troubles”.
The Bible has many metaphors, like:
John 6:35 Jesus said to them, ‘i am the bread of life; he who comes to me will not hunger, and he who believes in me will never thirst.’ Jesus is isn't really made out of bread. It's a metaphor.
Isaiah 64:8 "But now, O Lord, You are our Father, We are the clay, and You our potter; And all of us are the work of Your hand." We aren't literally made on of clay. It's a metaphor.
Window of heaven is not literally a window. It's a metaphor. Think about it, a window is something you can see through, but we no one on earth has seen the 3rd heaven nor the waters above the firmament. If it was literal, perhaps it would read the hidden door of heaven.
No one has seen a structure on the "sides" of the earth; no structure holding up a window in outer space with water on the other side of it. Do you honestly not understand that "windows of heaven" is a metaphor, or are you just pulling our leg?