A man's conduct has an influence upon the soul, making it pure or impure as the case may be.[73] Though man cannot see this effect, since the soul is an intellectual substance, God knows it. He also keeps a record of our deeds, and deals out reward and punishment in the world to come. This time will not come until he has created the number of souls which his wisdom dictates. At the same time there are also rewards and punishments in this world as an earnest of what is to come in the hereafter. A man is called righteous or wicked according as his good or bad deeds predominate. And the recompense in the next world is given for this predominating element in his character. A righteous man is punished for his few bad deeds in this world, and rewarded for his many good deeds in the world to come. Similarly the wicked man is paid for his good deeds in this world, while the punishment for his wickedness is reserved. This answers the old problem of the prosperity of the wicked and the misery of the righteous in this world. There are also sufferings of the righteous which are not in the nature of punishment for past conduct, but in view of the future so as to increase their reward in the world to come for the trials they endured without murmuring. The sufferings of little children come under this head. On the other hand, a sinner is sometimes well treated and his life prolonged for one of the following reasons: To give him time to repent, as in the case of Manasseh; that he may beget a righteous son, like Ahaz, the father of Hezekiah; to use him as God's tool to punish others more wicked than he--witness the rôle of Assyria as Isaiah describes it in chapter ten of his prophecies; for the sake of the righteous who is closely related to him, as Lot was saved for the sake of Abraham; or in order to make the punishment more severe later, as in the case of Pharaoh.