I will behave myself wisely - In the choice of principles to guide me; in my conduct in my family; in my official relations. This expresses a “desire” to act wisely, and a “purpose” to do it.
In a perfect way - In accordance with the perfect rules of right. I will make these my guide. I will “aim” to be perfect; I will have before me a perfect standard.
O when wilt thou come unto me? - Perhaps this would be better rendered, “When thou dost come unto me;” that is, When then dost visit me and my dwelling, thou shalt find that these are the principles which regulate and govern me in my house. The idea is that God would come to visit his habitation, and inspect his conduct; and that whenever this should occur, however often it might be, or however unexpectedly he might come, he should “always” find these principles governing him in his family. A man should so live that “whenever” God comes into his dwelling, or when anyone comes, or however narrow and searching may be the inspection, these principles shal be found to regulate his conduct.
I will walk within my house - Before my family; in the principles which shall govern me there.
With a perfect heart - Always aiming to do exactly that which is right: in my general conduct; in the rules by which I live; in my treatment of all under my charge and in my employ. The great principles of “right,” in everything - in the smallest matters - shall guide and govern me.