You know this, in Arabic language as well as in other languages, there is a grammatical expression called Bayatabar, and sometimes it is called Bayatabar-e-Kana and sometimes it is called Bayatabar-e-Mayukunu. Sometimes you use a you name something, somebody or something which is not present, but it was present once.
So that is Bayatabar-e-Kana. Sometimes you address something which is not there, but because it will be, so that is also correct, so that is called Bayatabar-e-Mayukunu, what will be. So kun by itself is not enough. You don’t stop there. Kun for yukun is a package deal. What was to be, that is to be, that is ordered, which is not there. So the order is addressed to that thing which is not there, but will be. So when it comes into being, as if the order was given to it and it obeyed. That is the expression.