1 Kings 11:4
“For it came to pass, when Solomon was old, that his wives turned away his heart after other gods: and his heart was not perfect with the Lord his God, as was the heart of David his father.”
Of the nations concerning which the Lord said unto the children of Israel, Ye shall not go in to them, neither shall they come in unto you: for surely they will turn away your heart after their gods: Solomon clave unto these in love.
And he had seven hundred wives, princesses, and three hundred concubines: and his wives turned away his heart.
For it came to pass, when Solomon was old, that his wives turned away his heart after other gods: and his heart was not perfect with the Lord his God, as was the heart of David his father.
For Solomon went after Ashtoreth the goddess of the Zidonians, and after Milcom the abomination of the Ammonites.
And Solomon did evil in the sight of the Lord, and went not fully after the Lord, as did David his father.
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“Let your heart therefore be perfect with the Lord our God, to walk in his statutes, and to keep his commandments, as at this day.”
“And if thou wilt walk before me, as David thy father walked, in integrity of heart, and in uprightness, to do according to all that I have commanded thee, and wilt keep my statutes and my judgments:”
“Let your heart therefore be perfect with the Lord our God, to walk in his statutes, and to keep his commandments, as at this day.”
“And Solomon loved the Lord, walking in the statutes of David his father: only he sacrificed and burnt incense in high places.”
“But if ye shall at all turn from following me, ye or your children, and will not keep my commandments and my statutes which I have set before you, but go and serve other gods, and worship them:”