HE

"Teach me, O Lord, the way of thy statutes; and I shall keep it unto the end. Give me understanding, and I shall keep thy law; yea, I shall observe it with my whole heart. Make me to go in the path of thy commandments; for therein do I delight. Incline my heart unto thy testimonies, and not to covetousness. Turn away mine eyes from beholding vanity; and quicken thou me in thy way. Stablish thy word unto thy servant, who is devoted to thy fear. Turn away my reproach which I fear: for thy judgments are good. Behold, I have longed after thy precepts: quicken me in thy righteousness."

"And I will put my spirit within you, and cause you to walk in my statutes, and ye shall keep my judgments, and do them. And ye shall dwell in the land that I gave to your fathers; and ye shall be my people, and I will be your God. I will also save you from all your uncleannesses"
"I do not this for your sakes, O house of Israel, but for mine holy name's sake, which ye have profaned"

I love how the Holy Spirit makes following God in any and every way a completely unreasonable requirement to the flesh.
I who am not worthy of redemption, am nevertheless redeemed from sin by the hand of the Lord, who saves all those that put their trust in Him. And so I trust.
David is asking God for something he knows he will receive, and has received, and is receiving. He delights in the law of the Lord, but asks for more with expectancy, understanding that we who believe and act on account of our belief are cleansed thereby ("Now ye are clean through the word which I have spoken unto you"; and again, "That he might sanctify and cleanse it with the washing of water by the word, That he might present it to himself a glorious church, not having spot, or wrinkle, or any such thing; but that it should be holy and without blemish.")
And now ought to be the age in which the promise of the Word of God written in the hearts of believers is fulfilled. And so Satan attempts to seduce us to excuse the sin we harbour and accuse those who preach against it of being Pharisaical, religious, legalistic, unreasonable, and hypocritical.
Grace into lasciviousness. Grace abundant by sin.
Not in my Bible.
Grace uproots lasciviousness. The true Grace of God gives sin no leg upon which to stand. Grace exposes who we are as sons and daughters of Adam that we might loathe ourselves though we be perfect and upright, and repent in dust and ashes.
Our righteousness is as filthy rags. Christ's righteousness is the glory of God revealed to men, the power of God to redeem those condemned in the flesh.
What then? Ought we to glorify our liberty in the flesh when we have through the Cross acknowledged its ultimate end? If then we glory in the flesh, we glory in that which condemns us, and therefore we glory in our own demise.
We ought to die daily, and exhort one another in the joy of the Lord to the same end of our greatest enemy. For certainly when the people of God went out to fight, they sent the praisers out before the men of war, and God gave them the victory.
Get out your swords, and let the High Praises of God proceed from your mouth as you go into battle with yourself. God will then precede your warfare, as through the Spirit ye do mortify (make dead, kill) the deeds of the flesh.

"Forasmuch then as Christ hath suffered for us in the flesh, arm yourselves likewise with the same mind: for he that hath suffered in the flesh hath ceased from sin; That he should no longer live the rest of his time in the flesh to the lusts of men, but to the will of God."