Evil is that for which they have sold their souls-- that they should deny what Allah has revealed, out of envy that Allah should send down of His grace on whomsoever of His servants He pleases; so they have made themselves deserving of wrath upon wrath, and there is a disgraceful punishment for the unbelievers.

And they followed what the Shaitans chanted of sorcery in the reign of Sulaiman, and Sulaiman was not an unbeliever, but the Shaitans disbelieved, they taught men sorcery and that was sent down to the two angels at Babel, Harut and Marut, yet these two taught no man until they had said, "Surely we are only a trial, therefore do not be a disbeliever." Even then men learned from these two, magic by which they might cause a separation between a man and his wife; and they cannot hurt with it any one except with Allah's permission, and they learned what harmed them and did not profit them, and certainly they know that he who bought it should have no share of good in the hereafter and evil was the price for which they sold their souls, had they but known this.

And when Allah made a covenant with those who were given the Book: You shall certainly make it known to men and you shall not hide it; but they cast it behind their backs and took a small price for it; so evil is that which they buy.