4. And therefore does the Scripture say, “These words the Lord spake 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 doth the LORD thy God require of thee, but to fear the LORD thy God, to walk in all His ways, and to love Him, and to serve the LORD thy God with all thy heart, and with all thy 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 thou mayest live, and thy seed, to love the LORD thy God, to hear His voice, to cleave unto Him; for this is thy life, and the length of thy 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.
Irenaeus | Against Heresies, 4.16.4