Albert Barnes Commentary Psalms 119:80

"Let my heart be perfect in thy statutes, That I be not put to shame. KAPH." — Psalms 119:80 (ASV)

Let my heart be sound ... - Hebrew, “Be perfect.” See the notes at (Job 1:1). The Septuagint here is “immaculate,” ἄμωμος amōmos. So the Latin Vulgate. It is the expression of a desire that the heart might be pure; that there might be no improper attachment for other objects; that there might be no defect of love to God.

That I be not ashamed - See the notes at (Psalms 119:6). A man has no occasion to be ashamed of a pure heart; and that which can alone keep us from being ultimately ashamed is sincerity, uprightness, and purity in the service of God.