"Before that," Ori explains, patiently. "Lirael, on Noxel? That's where our people come from. It's where Pothok originates. And Yeduthism. It was, I don't know, five thousand years ago? There was a war, and everyone left; it doesn't exist anymore, but it was once. My people settled on Jaith. It's not around anymore, either. You're a khatuloid, aren't you? They're from Noxel too."
That Ginzo is adopted is obvious; his father is human. But there were humans on Noxel, and they assumed if he's Yeduthi then his father must be too, but now they're wondering if they're wrong about that. If his father's from Alemeria he might not be Yeduthi at all, and that's why this guy doesn't know any of this; nobody taught him their history. But, no, he just said his father is, too.