I will behave myself wisely in a perfect way. O when wilt thou come unto me? I will walk within my house with a perfect heart.
I will behave myself wisely in a perfect way. The history (1 Samuel 18:14-15), by an undesigned coincidence which verifies the genuineness of both passages, uses almost the same words of David's behaviour - "David behaved himself wisely in all his ways." To 'behave wisely' is the result of meditating upon the testimonies of the Lord (Psalms 119:99), and stands in contrast to the sinful stupidity of the godless (Psalms 14:1-2). David sets forth his own practice, or at least aim. [The Hebrew letter he (h), in the future, implies effort]. "Perfect" or "upright" is a favourite word of David's (Psalms 18:23; Psalms 18:25; Psalms 15:2; Psalms 37:37; Psalms 64:4). God's words to Abraham are before his mind hero (Genesis 17:1).
O when wilt thou come unto me? - to bless and deliver me in my trouble, according to thy promise in Exodus 20:24, "In all places where I record my name I will come unto thee, and I will bless thee;" for in Zion, which has now become "the city of the Lord" (Psalms 101:8) by the presence of the ark of thy covenant, thou hast erected a 'record of thy name.' This abruptly-inserted prayer is the prelude of Psalms 102:1-28, which expands it. "Let my cry come unto thee" (Psalms 102:1) answers to "when wilt thou come unto me?" here. The coming of the Lord to the sufferer is inseparably joined with the coming of the sufferer's cry to Him. The ark had already come, as the phrase (Psalms 101:8), "the city of the Lord," proves; therefore the prayer here cannot be for its coming.
I will walk within my house with a perfect heart - with an upright or blameless heart (Psalms 78:72; 1 Kings 3:14; 1 Kings 9:4; 1 Kings 11:4; Proverbs 20:7).
Within my house - in my private life, as distinguished from David's public conduct in "the city of the Lord" (Psalms 101:8).