When Fir‘aun and Haamaan conspired and decided to kill Nabi Musa (‘alaihis salaam), one of Fir‘aun’s people who had secretly brought Imaan in Nabi Musa (‘alaihis salaam) exclaimed, “Are you killing a person merely because he declares, ‘My Lord is Allah’?”

Allah Ta‘ala recounts this incident in Surah Mu’min as follows:

وَ قَالَ رَجُلٌ مُّؤۡمِنٌ ٭ۖ مِّنۡ اٰلِ فِرۡعَوۡنَ یَکۡتُمُ اِیۡمَانَہٗۤ اَتَقۡتُلُوۡنَ رَجُلًا اَنۡ یَّقُوۡلَ رَبِّیَ اللّٰہُ

A believing man from the people of Fir‘aun who was concealing his Imaan said, “Do you wish to kill a man simply because he says, ‘My Lord is Allah’?” (Surah Mu’min v. 28)

(Extracted from Seeratul Mustafa pg. 204)