Reassurance to Prophet Muhammad during persecution

سُنَّةَ مَن قَدْ أَرْسَلْنَا قَبْلَكَ مِن رُّسُلِنَا ۖ وَلَا تَجِدُ لِسُنَّتِنَا تَحْوِيلًا

[That is Our] established way for those We had sent before you of Our messengers; and you will not find in Our way any alteration.