He isn't arguing that nothing came from something. He's more arguing that something just keeps coming from something and the entire concept of nothing is human fiction because it's counterintuitive in our daily lives. Like buildings don't just pop up, but all they really are is a rearrangement of what was already there. To us, we created it and assume that the earth and us had to be created. It reality, nature just kept rearranging over time and shit happened. That's all we and the earth are. There never was a void to fill. It was always something, and he discusses the evidence for why that is the case.