The title connects this psalm to David's sin with Bathsheba (2 Samuel 12:1-15)--a horrendous sin matched by the depth of confession and remorse in the psalm. By placing the psalm after "the prophet Nathan came to him," the title reminds the reader that confession and renewal are made possible by hearing God's word of judgment and hope.
The psalmist (David) prays for mercy, acknowledging that, although he has brought harm to Bathsheba and himself and death to Uriah, ultimately his sin is against God, who is totally justified in whatever sentence David deserves. Unlike the typical lament psalms, this one contains no accusation of God or the enemies, recognizing that the fault is David's alone (vv. 1-5). The confession that "I was born guilty, a sinner when my mother conceived me" (v. 5) is not a statement about original sin, a doctrine that was developed only later, nor does it mean that conception and birth are inherently sinful. Rather, the poet confesses that he, like all humans, is totally involved in a compromised and sinful world. The first stanza (vv. 1-9) begins and ends with a prayer for cleansing and blotting out the psalmist's transgressions.
"Create in me a clean heart, O God," prays David (v. 10), because only new creation will do. There is no hope for merely "patching up" what he has done. Not even the traditional practice of animal sacrifice, given by God for expiation of sin, will be effective in this case (v. 16). David needs a new heart, a new spirit, and only God can provide that. Because of this insight, Psalm 51--and especially this part of it--has frequently been used in Christian worship, either in the confession of sin or as an offertory prayer. Like the psalm, Christian worshipers recognize that, though their regular offerings have a good purpose, ultimately they can come before God only with "a contrite heart" (v. 17).
The final verses look beyond the life of David and pray for God to rebuild the walls of Jerusalem, apparently after the destruction of the city in 587 B.C.E. That, too, say the prophets, has been the result of Israel's sin, so confession is a necessary prelude to the petition for God to rebuild and restore. Once the city and its people have been made right by God, then normal sacrificial worship can be reinstituted (vv. 18-19).
1 Have mercy on me, O God,
according to your steadfast love;
according to your abundant mercy
blot out my transgressions.
2 Wash me thoroughly from my iniquity,
and cleanse me from my sin.
3 For I know my transgressions,
and my sin is ever before me.
4 Against you, you alone, have I sinned,
and done what is evil in your sight,
so that you are justified in your sentence
and blameless when you pass judgement.
5 Indeed, I was born guilty,
a sinner when my mother conceived me.
6 You desire truth in the inward being;*
therefore teach me wisdom in my secret heart.
7 Purge me with hyssop, and I shall be clean;
wash me, and I shall be whiter than snow.
8 Let me hear joy and gladness;
let the bones that you have crushed rejoice.
9 Hide your face from my sins,
and blot out all my iniquities.
10 Create in me a clean heart, O God,
and put a new and right* spirit within me.
11 Do not cast me away from your presence,
and do not take your holy spirit from me.
12 Restore to me the joy of your salvation,
and sustain in me a willing* spirit.
13 Then I will teach transgressors your ways,
and sinners will return to you.
14 Deliver me from bloodshed, O God,
O God of my salvation,
and my tongue will sing aloud of your deliverance.
15 O Lord, open my lips,
and my mouth will declare your praise.
16 For you have no delight in sacrifice;
if I were to give a burnt-offering, you would not be pleased.
17 The sacrifice acceptable to God* is a broken spirit;
a broken and contrite heart, O God, you will not despise.
18 Do good to Zion in your good pleasure;
rebuild the walls of Jerusalem,
19 then you will delight in right sacrifices,
in burnt-offerings and whole burnt-offerings;
then bulls will be offered on your altar.
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org