Pouring concrete is hard work. A solid base must be prepared before anything else is done. Then, when the concrete is poured, it must be shaped before it sets, because once set up, change is only possible if preceded by removal of what has already been laid down. If done correctly, a well-poured footing will last far beyond the original owner’s life…
Baker Books , 1500 Illustrations for Biblical Preaching, by Michael P. Green