4 And therefore does the Scripture say, “These words the Lord spoke to all the assembly of the children of Israel in the mount, and He added no more;” for, as I have already observed, He stood in need of nothing from them. And again Moses says: “And now Israel, what does the Lord your God require of you, but to fear the Lord your God, to walk in all His ways, and to love Him, and to serve the Lord your God with all your heart, and with all your soul?” Now these things did indeed make man glorious, by supplying what was wanting to him, namely, the friendship of God; but they profited God nothing, for God did not at all stand in need of man's love.
For the glory of God was wanting to man, which he could obtain in no other way than by serving God. And therefore Moses says to them again: “Choose life, that you may live, and your seed, to love the Lord your God, to hear His voice, to cleave unto Him; for this is your life, and the length of your days.” Preparing man for this life, the Lord Himself did speak in His own person to all alike the words of the Decalogue; and therefore, in like manner, do they remain permanently with us, receiving by means of His advent in the flesh, extension and increase, but not abrogation.
Source: Adversus haereses (New Advent)