٤. وَمَآ أَهْلَكْنَا مِن قَرْيَةٍ إِلَّا وَلَهَا كِتَابٌ مَّعْلُومٌ
٥. مَّا تَسْبِقُ مِنْ أُمَّةٍ أَجَلَهَا وَمَا يَسْتَـْٔخِرُونَ
4. And never did We destroy a township but there was a known decree for it. 5. No nation can advance its term, nor delay it.
Allah is informing us that He never destroys a township until He has established evidences for it and its allotted time has ended. When the time for a nation's destruction has come, He never delays it, and He never moves its appointed time forward. This was a message and a warning to the people of Makkah, telling them to give up their Shirk, their stubbornness and disbelief for which they deserved to be destroyed.