Ps. 51.10 (creation)

Create for me / a clean heart / O God
and renew / a steadfast spirit / in me

It is well known that the word 'create' is only applied to God. It is his unique prerogative and something man is entirely incapable of doing. Both thematically and literarily, this is the center of the psalm. Literarily, it falls directly in the middle (depending on whether you see the concluding lines as later additions). Thematically, it is the most important verse, clearly, of the entire psalm.

The fact that David sees a need for the creation of a clean heart is staggering. He does not, as he has indicated in every other verse, ask for it to be cleansed. His heart does not need to be 'un-sinned' or 'de-sinned' (vs. 7). It needs to be replaced entirely. What this says in a positive fashion must be understood in what it implies in a negative way--that his current heart is not only broken but, emphatically, beyond repair. It is only good to be discarded. This is not, perhaps, too surprising given the extent of his confession: David has traced his rebellion all the way back to his conception. Even in the womb when God asked for faithfulness and gave him wisdom, David rebelled, rejected and turned away from it. And yet, even this profound almost absolutizing of his rebellion, does not really prepare us for this. What David is asking for is what God did, over-and-over again, after the creation of the world: he would reduce it to its original state of water (as in the flood) and begin again. The only thing that could move his plan forward was a startling, unpredictable and awesome display of newness. For David to reach into these depths, and to pull from it this request is shocking in how utterly broken he perceives his current state (the heart not being the 'seat of emotion', but the center of the person, including his ability to reason, etc...). His guilt is so profound that he senses that his rebellion has indelibly ruined his heart and it is something that no amount of cleansing will be able to heal. I cannot help but think that this impulse comes from a sudden conviction (like the one received from Nathan), that explodes into David's conscience. The force of its suddenness, the extent of his rebellion, and his tenderness creates a situation wherein a line is drawn.

Jeremiah, when he envisions the new covenant, will allude to a similar cardio-replacement. God will remove the 'heart of stone' and replace it will a 'heart of flesh' and he will write on that heart his law. There is in this the sense that the old heart (there, the covenant) is incapable of its intended purpose. Here, though, that entire realm is centered into one man.

Within this new, clean vessel, the 'steadfast spirit' can be poured. The question is whose spirit this is: David's or God's. In the following verse David will ask that "your holy spirit, do not take from me". And, in verse after that, again, he will ask that "a willing spirit empower me". There is, indeed, no problem with God pouring out his spirit on people; when prophets (and kings...) are anointed the spirit will often rush upon them in a powerful and dynamic event that will often overwhelm the person. In light of the previous request for God to 'create' a new heart it seems to me that David is asking her to also be infused with the spirit of God--that it is God's spirit that create this new 'steadfastness' on David's part. Whereas his spirit has been on of inconstancy and rebellion, this new one of God, and given by God, will be 'constant' (something that is very dear to David's heart with his own constant concern for loyalty...).