1 Kings 14:8

And rent the kingdom away from the house of David, and gave it thee: and yet thou hast not been as my servant David, who kept my commandments, and who followed me with all his heart, to do that only which was right in mine eyes;

Hast not been as my servant David - who, though he fell into grievous sins, repented, and always maintained the pure worship of God, as enjoined by the law. David lived under the ancient dispensation, when, it must be always remembered, the breach of the commandments, in their full and spiritual meaning, was no breach of the Sinai covenant, since heart sins were neither punished by depth nor expiated by sacrifice; and since provision was made even for defects in outward obedience, sacrifices being appointed for all offences that were not committed presumptuously and with a high hand (Numbers 15:22). The precept, therefore, "Thou shalt love the Lord thy God with all thy heart," considered in connection with the Sinai covenant, only requires such a regard to the Deity as that obedience be given to the letter of His commandments. It does not in this view demand sinless perfection, but such an obedience as fallen creatures have actually yielded;-David, for instance, who is said 'to have kept God's commandments, followed him with all his heart, and did that only which was right in his eyes' (cf. 2 Kings 23:25: see Erskine, 'On the Nature of the Sinai Covenant').