I have waited, waited for the LORD,
and he stooped toward me and heard my cry.
And he put a new song into my mouth,
a hymn to our God.
Sacrifice or offering you wished not,
but ears open to obedience you gave me.
Holocausts or sin-offerings you sought not;
then said I, “Behold I come.”
“In the written scroll it is prescribed for me,
to do your will, O my God, is my delight,
and your law is within my heart!”
I announced your justice in the vast assembly;
I did not restrain my lips, as you, O LORD, know.
A thanksgiving (Ps 40:2–13) has been combined with a lament (Ps 40:14–17) that appears also in Ps 70. The psalmist describes the rescue in spatial terms—being raised up from the swampy underworld to firm earth where one can praise God (Ps 40:2–4). All who trust God will experience like protection (Ps 40:5–6)! The Psalm stipulates the precise mode of thanksgiving: not animal sacrifice but open and enthusiastic proclamation of the salvation just experienced (Ps 40:7–11). A prayer for protection concludes (Ps 40:12–17).
The psalmist, who knows that the conformation of his mind and desire to the will and revelation of God takes the place of sacrifice, is a type for Jesus, whose obedience unto death replaced all cultic sacrifice and accomplished once for all the perfect sacrifice. The psalmist with his praise and piety still must pray for salvation from suffering and sin. That is where we all are. But our prayers are made in hope, because the sacrifice for sin has been made for us once for all.
– James Mays
May the virtues of faith, hope, and love go with you today – DV.
 Donald Senior, John J. Collins, and Mary Ann Getty, eds., The Catholic Study Bible, 2nd Ed.: Notes, 2nd ed., vol. 2 (New York: Oxford University Press, 2011), 756.