Preservation of posterity

وَءَايَةٌ لَّهُمْ أَنَّا حَمَلْنَا ذُرِّيَّتَهُمْ فِى ٱلْفُلْكِ ٱلْمَشْحُونِ

And a sign for them is that We carried their forefathers in a laden ship.