Qur'an 40:28

وَقَالَ رَجُلٌ مُّؤْمِنٌ مِّنْ ءَالِ فِرْعَوْنَ يَكْتُمُ إِيمَـٰنَهُۥٓ أَتَقْتُلُونَ رَجُلًا أَن يَقُولَ رَبِّىَ ٱللَّهُ وَقَدْ جَآءَكُم بِٱلْبَيِّنَـٰتِ مِن رَّبِّكُمْ ۖ وَإِن يَكُ كَـٰذِبًا فَعَلَيْهِ كَذِبُهُۥ ۖ وَإِن يَكُ صَادِقًا يُصِبْكُم بَعْضُ ٱلَّذِى يَعِدُكُمْ ۖ إِنَّ ٱللَّهَ لَا يَهْدِى مَنْ هُوَ مُسْرِفٌ كَذَّابٌ

And a believing man of Pharaoh's family, who hid his faith, said: Would ye kill a man because he saith: My Lord is Allah, and hath brought you clear proofs from your Lord? If he is lying, then his lie is upon him; and if he is truthful, then some of that wherewith he threateneth you will strike you. Lo! Allah guideth not one who is a prodigal, a liar.