But these two taught no one until they had said , " We are but a trial , therefore , do not disbelieve [ in God 's guidance ] . " So men learnt from them that by which they caused discord between man and wife ; but they harmed no one thereby , except by the command of God ; [ on the contrary ] , these people learned that which would harm them and do them no good , knowing full well that whoever acquired [ this knowledge ] would have no share in the Hereafter .