Sin and disobedience would not cancel God"s promises to David in the covenant. They would bring discipline on the offenders, but God swore to deliver the blessings He had promised David. [source][source][source]
Since Jesus Christ, David"s descendant, has not yet ruled over Israel as these promises guarantee, we should look for a literal fulfillment of them in the future. This means He will rule on the earth, since this is what God promised David ( 2 Samuel 7:5-16). For this reason we look for an earthly reign of Messiah, not just a heavenly reign over the hearts of all believers. [1] The hope of an earthly reign over Israel is what distinguishes premillennialists from amillennialists and postmillennialists. This hope rests on a literal interpretation of God"s promises in the Davidic Covenant (cf. Psalm 89:3-4; Psalm 89:27-29; Psalm 89:35-37; Psalm 89:49). [2][source]