4 The Jews then were troubled. What is this? “Why does He these things on the sabbath days?” And especially at those words of the Lord, “My Father works hitherto, and I work.” Their carnal understanding of this, that God rested on the seventh day from all His works, “troubled them.” For this is written in Genesis, and most excellently written it is, and on the best reasons. But they thinking that God as it were rested from fatigue on the seventh day after all, and that He therefore blessed it, because on it He was refreshed from His weariness, did not in their foolishness understand, that He who made all things by the Word, could not be wearied.
Let them read, and tell me how could God be wearied, who said, “Let it be made, and it was made.” Today if a man could so do, as God did, how would he be wearied? He said, “Let there be light, and the light was made.” Again, “Let there be a firmament, and it was made:” if indeed He said, and it was not done, He was wearied. In another place briefly, “He spoke, and they were made; He commanded, and they were created.” He then who works thus, how does He labour? But if He labour not, how does He rest?
But in that sabbath, in which it is said that God rested from all His works, in the Rest of God our rest was signified; because the sabbath of this world shall be, when the six ages shall have passed away. The six days as it were of the world are passing away. One day has passed away, from Adam unto Noe; another from the deluge unto Abraham; the third from Abraham unto David; the fourth from David unto the carrying away into Babylon; the fifth from the carrying away into Babylon unto the advent of our Lord Jesus Christ.
Now the sixth day is in passing. We are in the sixth age, in the sixth day. Let us then be reformed after the image of God, because that on the sixth day man was made after the image of God. What formation did then, let reformation do in us, and what creation did there, let creating-anew do in us. After this day in which we now are, after this age, the rest which is promised to the saints and prefigured in those days, shall come. Because in very truth too, after all things which He made in the world, He has made nothing new in creation afterwards.
The creatures themselves shall be transformed and changed. For since the creatures were fashioned, nothing more has been added. But nevertheless, if He who made did not rule the world, what is made would fall to ruin: He cannot but administer that which He has made. Because then nothing has been added to the creation, He is said to have rested from all His works; but because He does not cease to govern what He made, rightly did the Lord say, “My Father works even hitherto.” Attend, Beloved.
He finished, He is said to have rested; for He finished His works, and has added no more. He governs what He has made; therefore He does not cease to work. But with the same facility that He made, with the same does He govern. For do not suppose, brethren, that when He created He did not labour, and that He labours in that He governs: as in a ship, they labour who build the ship, and they who manage it labour too; for they are men. For with the same facility wherewith “He spoke and they were made,” with the same facility and judgment does He govern all things by the Word.
Source: Sermons on Selected Lessons of the New Testament (New Advent)