He said:

“Among the intractable difficulties they must face is this question: when the indivisible part comes into being, what receives that very coming into being? For occurrences are accidents, and once the originated thing exists, its coming into being has ceased. Since one of their principles is that accidents cannot be separate from substances, they are compelled to posit coming into being in some existent and through some existence.”

I say:

Someone who maintains that bringing into being is identical with the thing brought into being, that the created thing is identical with creation, and that the effect is identical with the act—as the Ash'arīs hold—does not concede that coming into being is an accident, or that it has a substrate, let alone that it is something positively existent. However, he has already refuted this position and established that an effect necessarily requires an act.

It may then be said:

The act of bringing into being subsists in the agent who brings things into being. The coming into being of an originated thing is not an existent accident subsisting in something, over and above the originator’s act of bringing it into being.

It may also be said:

This rests on the assumptions that the nonexistent is a thing and that essences in external reality are additional to their existence. Both assumptions are false.

Even supposing this were correct, the answer would be:

What receives coming into being is those entities and essences.

However, what he has mentioned can be established through his associates’ well-known line of argument: that whatever comes into being