Covenant faithfulness.
The psalmist, as a just returned, or as a speedily returning, exile—one just making preparations for his return—is anxious to be right hearted in relation to this new national restoration, and he is anxious to help others to be right hearted. So he thinks over aloud his personal experiences of God's dealings with himself (Psalms 103:1-22.); the marvels of God's handiwork in nature (Psalms 104:1-35.); the overrulings of Divine providence in the national history (Psalms 105:1-45.); and the causes for national humiliation (Psalms 106:1-48.). The leading idea before us, in this and the following psalm, is this. God and Israel entered into mutual covenant. Read the national story how you may, you will find that God has always been faithful to his pledges in that covenant, and the people have constantly been unfaithful. The marvel of mercy is that God's patient and persistent faithfulness triumphs at last over man's wilfulness and unfaithfulness.
I. GOD MADE COVENANT WITH HIS PEOPLE IN OLD TIMES. It is not only that God made promises the marvel of Divine grace is, that God should condescend to stand on man's platform, and join with man in putting himself under solemn pledge. Covenant making is an idea of early tribal times, when legal documents could not be written and signed. Illustrate God's covenant with Abraham, which was renewed again and again. Dwell on the fact that there were two persons, and two sets of conditions, in a covenant; and each was released if the other broke his terms. Lead on to show how the name is preserved in relation to the mission of our Lord Jesus Christ.
II. GOD WAS ALWAYS FAITHFUL TO HIS PLEDGES IN COVENANT. This the psalmist treats as an unquestionable historical fact. God was true to Abraham, Isaac, Israel in Egypt, Joseph. True to covenant in dealing with Pharaoh, Israel's oppressor. True in bringing Israel at last to the promised land. Providences are only rightly read as God's fulfilment of his covenant. That which is true of Israel is true of our persona lives. God has been to us Provider, Guide, Ruler, and Overruler.
III. GOD MAY BE FULLY TRUSTED TO PROVE FAITHFUL IN NEW SCENES. This is the appeal which the psalmist makes to the returning exiles. God has ever been faithful to your fathers; he will be faithful to you. So our trust is in what we know God to be; and we know him by what he has done, and does. He is the "faithful Promiser;" we may fully trust him.—R.T.