28:9 Know - So as to love and serve him. Words of knowledge in scripture - use commonly imply affection and practice. Or, acknowledge him, as thy God, by loving and obeying him. Searcheth - If thou dost only put on a profession of religion to please me, or if thy obedience to God be unsincere, thou mayest indeed deceive me, but thou canst not deceive him, for he searcheth the motions of thy heart. Cast thee off - Notwithstanding all his promises to me and to my seed, and that great honour and favour which he hath shewed thee.
28:1-10 During David's last sickness, many chief priests and Levites were at Jerusalem. Finding himself able, David spoke of his purpose to build a temple for God, and of God's disallowing that purpose. He opened to them God's gracious purposes concerning Solomon. David charged them to cleave stedfastly to God and their duty. We cannot do our work as we should, unless we put on resolution, and fetch in strength from Divine grace. Religion or piety has two distinct parts. The first is knowledge of God, the second is worship of God. David says, Know thou the God of thy father, and serve him with a perfect heart and a willing mind. God is made known by his works and word. Revelation alone shows the whole character of God, in his providence, his holy law, his condemnation of sinners, his blessed gospel, and the ministration of the Spirit to all true believers. The natural man cannot receive this knowledge of God. But thus we learn the value of the Saviour's atonement, and of the sanctification of the Holy Spirit, and are influenced to walk in all his commandments. It brings a sinner to his proper place at the foot of the cross, as a poor, guilty, helpless worm, deserving wrath, yet expecting every thing needful from the free mercy and grace of God our Father, and the Lord Jesus Christ. Having been forgiven much, the pardoned sinner learns to love much.
