Surah Ali 'Imran · Ayah 144

وَمَا مُحَمَّدٌ إِلَّا رَسُولٌۭ قَدْ خَلَتْ مِن قَبْلِهِ ٱلرُّسُلُ ۚ أَفَإِي۟ن مَّاتَ أَوْ قُتِلَ ٱنقَلَبْتُمْ عَلَىٰٓ أَعْقَٰبِكُمْ ۚ وَمَن يَنقَلِبْ عَلَىٰ عَقِبَيْهِ فَلَن يَضُرَّ ٱللَّهَ شَيْـًۭٔا ۗ وَسَيَجْزِى ٱللَّهُ ٱلشَّٰكِرِينَ

Wa maa Muhammadun illaa Rasoolun qad khalat min qablihir Rusul; afa'im maata aw qutilan qalabtum 'alaaa a'qaabikum; wa mai yanqalib 'alaa aqibihi falai yadurral laaha shai'aa; wa sayajzil laahush shaakireen

Muhammad is not but a messenger. [Other] messengers have passed on before him. So if he was to die or be killed, would you turn back on your heels [to unbelief]? And he who turns back on his heels will never harm Allah at all; but Allah will reward the grateful.