The Quran

Preface

وَقالَ رَجُلٌ مُؤمِنٌ مِن آلِ فِرعَونَ يَكتُمُ إيمانَهُ أَتَقتُلونَ رَجُلًا أَن يَقولَ رَبِّيَ اللَّهُ وَقَد جاءَكُم بِالبَيِّناتِ مِن رَبِّكُم ۖ وَإِن يَكُ كاذِبًا فَعَلَيهِ كَذِبُهُ ۖ وَإِن يَكُ صادِقًا يُصِبكُم بَعضُ الَّذي يَعِدُكُم ۖ إِنَّ اللَّهَ لا يَهدي مَن هُوَ مُسرِفٌ كَذّابٌ

Yusuf Ali

A believer, a man¹ from among the people of Pharaoh, who had concealed his faith, said: “Will ye slay a man because he says, ?My Lord is God.?- when he has indeed come to you with Clear (Signs) from your Lord? and if he be a liar, on him is (the sin of) his lie: but, if he is telling² the Truth, then will fall on you something of the (calamity) of which he warns you: Truly God guides not one³ who transgresses and lies!

There is nothing to justify the identification of this man with the man mentioned in 28:20, who warned Moses long before Moses had received his mission. On the contrary, in this passage, the man is evidently speaking after Moses had received his mission, preached to Pharaoh, and got a certain amount of success, for which Pharaoh and his people were trying to seek his life. Moses had evidently already brought his Clear Signs.
A commonsense view is put before them by an Egyptian who loves his own people and does not wish them to perish in sin. “Will you kill this man for calling on God? Have you not seen his character and behaviour? Do you not see the 'Clear Signs’ about him that bespeak his credentials? Suppose for a moment that he is a liar and pretender: he will suffer for his falsehood, but why should you turn against God? But suppose that he is really inspired by God to tell you the truth and warn you against evil, what will be your fate when God’s Wrath descends? For it must descend if he is a true Messenger sent by God.”
This is with reference to the “Clear Signs”. 'They are Signs of God’s guidance, for God would never guide a man who exceeds the bounds of truth and tells you lies! Such a man is bound to be found out!'