Surah Al-Imran, ayah 144

3:144

وَمَا مُحَمَّدٌ إِلَّا رَسُولٞ قَدۡ خَلَتۡ مِن قَبۡلِهِ ٱلرُّسُلُۚ أَفَإِيْن مَّاتَ أَوۡ قُتِلَ ٱنقَلَبۡتُمۡ عَلَىٰٓ أَعۡقَٰبِكُمۡۚ وَمَن يَنقَلِبۡ عَلَىٰ عَقِبَيۡهِ فَلَن يَضُرَّ ٱللَّهَ شَيۡـٔٗاۚ وَسَيَجۡزِي ٱللَّهُ ٱلشَّٰكِرِينَ ١٤٤

Wamā muhammadun illā rasūlun qad khalat min qablihir-rusulu afa'im māta aw qutilanqalabtum 'alā a'qābikum waman yanqalib 'alā 'aqibayhi falan yadurrallāha shay'an wasayajzillāhush-shākirīn

Muḥammad 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 Allāh at all; but Allāh will reward the grateful.