Is it not a lesson for the successors of the past generations that had We wanted, We could have punished them for their sins, sealed their hearts and deprived them of hearing? 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 And We found no covenant in most of them; and most of them We found ungodly. 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 Moses said: "O Pharaoh, I have been sent by the Lord of all the worlds; 104 incumbent upon me is that I say nothing of Allah except the truth. I bring you a clear proof from your Lord. So let the Children of Israel depart with me' 105 Said [Pharaoh]: "If thou hast come with a sign, produce it - if thou art a man of truth!" 106 Therefore Moosa put down his staff – it immediately turned into a visible python. 107 and he drew forth his hand, and lo! it appeared [shining] white to the beholders. 108