ISIS could—and very much wanted to—“transform Iran into pools of blood,” Adnani said. After all, Iran was the “bitterest enemy” of the Islamic State.

But al Qaeda long has been known to have deep, complex relations with Iran. And so ISIS, which grew out of a branch of al Qaeda in Iraq, “held back its soldiers and repressed its rage over the years to preserve the unity” of al Qaeda’s ranks.

“So let history record that Iran owes an invaluable debt to al Qaeda,” he added.