Psalms 51:10 - Matthew Poole's English Annotations on the Holy Bible

Create in me a clean heart; seeing I have not only defiled myself by these actual sins, but also have a most filthy heart, corrupted even from my birth, Psalms 51:5, which nothing but God's almighty and creating power can purify, do thou effectually work in me a holy frame of heart, whereby both my inward filth may be purged away, and I may be prevented from falling into such actual and scandalous sins. Renew that good temper which before this apostacy I had in some measure, be pleased graciously to restore it to me with advantage. Right, Heb. firm, or constant, or steadfast, that I may not be so easily shaken and cast down by temptation, as I have been, but that my resolution may be more fixed and unmovable. Spirit; temper or disposition of soul or spirit; as the word spirit is very frequently used in Scripture. Within me, Heb. in my inward parts. He wisely strikes at the root and cause of all sinful actions.