The expedient of new revelations completing, altering, or abrogating former ones had played an important part in the legislative work of Mohammed. Now, he had never considered that by his death the spring would be stopped, although completion was wanted in every respect. For, without doubt, Mohammed felt his weakness in systematizing and his absence of clearness of vision into the future, and therefore he postponed the promulgation of divine decrees as long as possible, and he solved only such questions of law as frequently recurred, when further hesitation would have been dangerous to his authority and to the peace of the community. At Mohammed's death, all Arabs were not yet subdued to his authority. The expeditions which he had undertaken or arranged beyond the northern boundaries of Arabia, were directed against Arabs, although they were likely to rouse conflict with the Byzantine and Persian empires. It would have been contrary to Mohammed's usual methods if this had led him to form a general definition of his attitude towards the world outside Arabia. As little as Mohammed, when he invoked the Meccans in wild poetic inspirations to array themselves behind him to seek the blessedness of future life, had dreamt of the possibility that twenty years later the whole of Arabia would acknowledge his authority in this world, as little, nay, much less, could he at the close of his life have had the faintest premonition of the fabulous development which his state would reach half a century later. The subjugation of the mighty Persia and of some of the richest provinces of the Byzantine Empire, only to mention these, was never a part of his program, although legend has it that he sent out written challenges to the six princes of the world best known to him. Yet we may say that Mohammed's successors in the guidance of his community, by continuing their expansion towards the north, after the suppression of the apostasy that followed his death, remained in Mohammed's line of action. There is even more evident continuity in the development of the empire of the Omayyads out of the state of Mohammed, than in the series of events by which we see the dreaded Prince-Prophet of Medina grew out of the "possessed one" of Mecca. But if Mohammed had been able to foresee how the unity of Arabia, which he nearly accomplished, was to bring into being a formidable international empire, we should expect some indubitable traces of this in the Qorân; not a few verses of dubious interpretation, but some certain sign that the Revelation, which had repeatedly, and with the greatest emphasis, called itself a "plain Arabic Qorân" intended for those "to whom no warner had yet been sent," should in future be valid for the 'Ajam, the Barbarians, as well as for the Arabs.