Does it not guide the people who inherit the land from former people that We can punish them for their sins if We will? And seal up their hearts so that they would not be able to lend an ear to words of guidance? 100 To those [earlier] communities - some of whose stories We relate to you - there had indeed come Messengers with clear proofs, but they would not believe what they had once rejected as false. Thus it is that Allah seals the hearts of those who deny the truth. 101 We did not find the covenant upheld by the majority of them, but We found most of them evildoers. 102 After those We sent forth Moses with Our signs to Pharaoh and his nobles, but they dealt with Our signs unjustly. Observe, then, what happened to the mischief-makers. 103 And Musa said: O Firon! surely I am an apostle from the Lord of the worlds: 104 Approved upon condition that I speak concerning Allah nothing but the truth. I come unto you (lords of Egypt) with a clear proof from your Lord. So let the Children of Israel go with me. 105 Pharaoh said: if you have brought a sign, then bring it forth if you are truthful.' 106 So he cast his staff; and behold, it was a serpent manifest. 107 And he drew forth his hand, when lo: it was white unto the beholders. 108