Surah Ghafir 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 from the family of Pharaoh who concealed his faith said, "Do you kill a man [merely] because he says, 'My Lord is Allāh' while he has brought you clear proofs from your Lord? And if he should be lying, then upon him is [the consequence of] his lie; but if he should be truthful, there will strike you some of what he promises you. Indeed, Allāh does not guide one who is a transgressor and a liar.

Translation: Saheeh International

Tafsir

Then said a believing man from among Pharaoh’s folk — this is said to have been his paternal cousin — who had concealed his faith ‘Will you slay a man for saying “My Lord is God” even though he has also brought you clear signs manifest miracles from your Lord? If he is lying then his mendacity will be to his own …

Excerpt from Tafsir al-Jalalayn, commentary on 40:28, via Quran.com. The reader has the full commentary and 9 more tafsirs.