17 And this voice we shall hear, if we show the same earnestness as he did. And we shall show this earnestness, if we do this which I say. When you depart, while what you have heard is yet warm within you, exhort one another! And just as you each salute at parting, so let every one go from hence with an admonition, and say to his neighbour, “Observe and remember that thou keep the commandment;” and thus shall we assuredly get the mastery. For when friends also dismiss one with such counsel; and on one's return home, one's wife again admonishes one to the same effect; and our word keeps its hold on you when alone; we shall soon shake off this evil habit.
I know, indeed, that you marvel why I am so earnest respecting this precept. But discharge the duty enjoined, and then I will tell you. Meanwhile, this I say; that this precept is a divine law; and it is not safe to transgress it. But if I shall see it rightly performed, I will speak of another reason, which is not less than this, that you may learn that it is with justice I make so much ado about this law. But it is now time to conclude this address in a prayer. Wherefore, let us all say in common, “O God, Who willest not the death of a sinner, but that he should be converted and live; grant that we, having discharged this and every other precept, may be found worthy so to stand at the tribunal of Your Christ, that having enjoyed great boldness, we may attain the kingdom to Your glory.
For to You belongs glory, together with Your only begotten Son, and the Holy Ghost, now and ever, and world without end.” Amen.
Source: Homilies on the Statues (New Advent)