Pondering this passage from Marie Mutsuki Mockett’s Where the Dead Pause and the Japanese Say Goodbye, page 151:
He picked a dish up off the the altar—the gesture was meant to seem casual, but it was full of dramatic flourish. Look at this dish right here, he said. Will this be here in a million years? No. So it is here. But it is not here. You know about atoms? Kukai thought about atoms long before we were able to see them. If we had a thread that was thin enough, we could thread it through the cup and it would go out the other side. And so the cup is here, but it is not here. If enough time were to go by, the cup would not be here, but if we were to look for its atoms, we would find them scattered around the universe, which means the cup would be everywhere. And in the same way, the Buddha is everywhere. The point of Shingon is not to be nothing, but to understand that everything is and is not actually concrete. That’s it.