I. Consider the "new songs" already put into the mouths of Christians. (1) Coming to Christ and conversion to God are materials for a "new song." (2) Few leave the Lord's Table after their first communion without a new song in their mouth of praise to their God. (3) God in springtime renews the face of the earth, and there are corresponding renewings of our spiritual life. (4) A good hope when first given is a new song; and this good hope when renewed, when made more alive and effectual, is a new song.
II. Grand and glorious new songs are in our future. There is the song of victory over death. The first moment after death will put a new song in our mouth, and as certainly more certainly our entrance to heaven will do the same.
III. Let the text excite us to go through life with songs. Let us sing that which God gives us to sing. In plain words, let us acknowledge our obligations to "the Father of all mercies" and the God of all consolation; and let us so acknowledge them as to awaken praise to our God. We are all called to be singers, and we are called to sing new songs.
S. Martin, Comfort in Trouble,p. 106.
References: Psalms 40:3. J. Stalker, The New Song,p. 9. Psalms 40:4. Spurgeon, Sermons,vol. xxx., No. 1784.Psalms 40:5. Homiletic Quarterly,vol. ii., p. 273.Psalms 40:6-8. E. Irving, Sermons,vol. i., p. 1.