1 Kings 11:4 - Joseph Benson’s Commentary on the Old and New Testaments

For it came to pass when Solomon was old, &c. Having now reigned nigh thirty years, when it might have been expected that experience would have made him wiser; then God suffered him to fall so shamefully, that he might to all succeeding generations be an example of the folly and weakness of the wisest and the best men, when left to themselves. His wives turned away his heart after other gods Not that they altered his judgment respecting the true God and idols, which is not credible; but they obtained from him a public indulgence for their idol-worship, and possibly persuaded him to join with them sometimes in the outward acts of it; or at least, in their feasts upon their sacrifices, which was a participation of their idolatry. And his heart was not perfect with the Lord his God He did not entirely forsake the service of Jehovah, but joined the worship of other gods with him, which he never could have done, after the true knowledge which he had of God, and the solemn profession he had made of adherence to him, unless he had been greatly fallen.