This Gospel teaches us to note particularly the good tidings which God has granted us, that we may here on earth say to each other, “Thy sins are forgiven thee,” so that with the people here spoken of we may marvel and glorify God, Which had given such power unto men. And it is indeed a great power that one Christian may say to another: My brother, be of good cheer, you have a gracious God; only believe the assurance which I give you in Christ’s name and it is as certain as if God Himself had said to you, Thy sins are forgiven thee. Such power, as we hear, originated in Christ and is now given unto men, especially to those who are in office and are commanded to preach the Gospel, that is, repentance and forgiveness of sins, in Jesus’ name. Other Christians, although they are not in that office, also have the command, in case of necessity, to comfort you when you are troubled on account of your sins, and to say: Why are you troubled? I, as a Christian, assure you that you are wronging yourself; God is not unmerciful unto you. You are for Christ’s sake to put all your trust in His grace. You are to comfort yourself as surely with these words as if Christ spake them in person from heaven. (Luther’s House Postil, Sermon for the Nineteenth Sunday after Trinity, Volume 3, p. 831-832)

The sum of the matter is that our Lord boldly tells the Pharisees that they do not know what it is to keep the Sabbath day and to sanctify it. According to your idea, He tells them, it is sanctifying the Sabbath day to be altogether idle and to do no work whatever. No, this is not the meaning of the Sabbath day. To sanctify the Sabbath day means to hear the Word of God and to help our neighbor wherever we can. God does not want a keeping of the Sabbath day in which our neighbor is neglected or left to suffer. For if I serve and help my neighbor, I have kept the Sabbath as it should be kept, and have done a truly good work. This doctrine concerning the Sabbath day shows us how to understand the third commandment aright, according to which we are required, not to be idle or to do nothing, but to hear the Word of God and to live according to that Word. And what does that Word teach us? It directs us, according to the second table, to love and serve one another. This God wants us to learn on the Sabbath day. Hence it must also follow that we are not desecrating the Sabbath day by such good works as these. (Luther’s House Postil, Sermon for the Seventeenth Sunday after Trinity, Volume 3, p. 815)