Thomas Aquinas

“ Further, rest is opposed to movement, or to labor, which movement causes. But, as God produced His work without movement and without labor, He cannot be said to have rested on the seventh day from His work. ”

“ It may also be added that in continuous movement, so long as any movement further is possible, movement cannot be called completed till it comes to rest, for rest denotes consummation of movement. Now God might have made many other creatures besides those which He made in the six days, and hence, by the fact that He ceased making them on the seventh day, He is said on that day to have consummated His work. ”

“ Further, nothing is said to be complete to which many things are added, unless they are merely superfluous, for a thing is called perfect to which nothing is wanting that it ought to possess. But many things were made after the seventh day, as the production of many individual beings, and even of certain new species that are frequently appearing, especially in the case of animals generated from putrefaction. ”