And when he was now old, his heart was turned away by women to follow strange gods: and his heart was not perfect with the Lord his God, as was the heart of David his father.

And it cometh to pass, at the time of the old age of Solomon, his wives have turned aside his heart after other gods, and his heart hath not been perfect with Jehovah his God, like the heart of David his father.

For it came about that when Solomon was old, his heart was turned away to other gods by his wives; and his heart was no longer true to the Lord his God as the heart of his father David had been.

For it came to pass, when Solomon was old, that his wives turned away his heart after other gods; and his heart was not whole with the LORD his God, as was the heart of David his father.

And when now he was old, his heart was perverted by the women, so that he followed strange gods. And his heart was not perfect with the Lord his God, as was the heart of his father David.

Old - About fifty or fifty-five. From his age at his accession (1-Kings 2:2 note) he could not have been more than about sixty at his death.
The true nature of Solomon's idolatry was neither complete apostasy - an apostasy from which there could be no recovery; nor a mere toleration, rather praise-worthy than blameable. Solomon did not ever openly or wholly apostatize. He continued his attendance on the worship of Yahweh, and punctually made his offerings three times a year in the temple 1-Kings 9:25; but his heart was not "perfect" with God. The religious earnestness of his younger days was weakened by wealth, luxury, sensualism, an increasing worldliness leading him to worldly policy and latitudinarianism arising from contact with all the manifold forms of human opinion. His lapse into deadly sin was no doubt gradual. Partly from ostentation, partly from that sensualism which is the most common failing of Oriental monarchs, he established a harem on a grand and extraordinary scale. To gratify "strange women," i. e., foreigners, admitted either from worldly policy, or for variety's sake, he built magnificent temples to their false gods, right over against Jerusalem, as manifest rivals to "the temple." He thus became the author of a syncretism, which sought to blend together the worship of Yahweh and the worship of idols - a syncretism which possessed fatal attractions for the Jewish nation. Finally, he appears himself to have frequented the idol temples 1-Kings 11:5, 1-Kings 11:10, and to have taken part in those fearful impurities which constituted the worst horror of the idolatrous systems, thus practically apostatising, though theoretically he never ceased to hold that Yahweh was the true God.

For it came to pass, when Solomon was old, [that] his wives turned away his heart after other gods: and his heart was not (c) perfect with the LORD his God, as [was] the heart of David his father.
(c) He did not serve God with a pure heart.

And it came to pass, when Solomon was old,.... Toward the latter end of his reign, when he might be near sixty years of age; for Rehoboam his son and successor was forty one when he began to reign, 1-Kings 14:21 which is observed either as an aggravation of the sin of Solomon, that in his old age, when by long experience he might have been thought to be still wiser, and less lustful: and yet
that his wives turned away his heart after other gods; or as pointing at the advantage his wives took of his age:
and his heart was not perfect with the Lord his God, as was the heart of David his father; who, though guilty of many sins, never inclined to idolatry; his heart was always right in that point, and sincere in his worship, see Psalm 18:20.

when Solomon was old--He could not have been more than fifty.
his wives turned away his heart after other gods--Some, considering the lapse of Solomon into idolatry as a thing incredible, regard him as merely humoring his wives in the practice of their superstition; and, in countenancing their respective rites by his presence, as giving only an outward homage--a sensible worship, in which neither his understanding nor his heart was engaged. The apology only makes matters worse, as it implies an adding of hypocrisy and contempt of God to an open breach of His law. There seems no possibility of explaining the language of the sacred historian, but as intimating that Solomon became an actual and open idolater, worshipping images of wood or stone in sight of the very temple which, in early life, he had erected to the true God. Hence that part of Olivet was called the high place of Tophet (Jeremiah 7:30-34), and the hill is still known as the Mount of Offense, of the Mount of Corruption (2-Kings 23:13).

In the time of old age, when the flesh gained the supremacy over the spirit, they turned his heart to other gods, so that it was no longer wholly with Jehovah, his God. שׁלם, integer, i.e., entirely devoted to the Lord (cf. 1-Kings 8:61), like the heart of David his father, who had indeed grievously sinned, but had not fallen into idolatry.

Was old - As having now reigned nigh thirty years. When it might have been expected that experience would have made him wiser: then God permitted him to fall so shamefully, that he might be to all succeeding generations an example of the folly, and weakness of the wisest and the best men, when left to themselves. Turned his heart - Not that they changed his mind about the true God, and idols, which is not credible; but they obtained from him a publick indulgence for their worship, and possibly persuaded him to join with them in the outward act of idol - worship; or, at least, in their feasts upon their sacrifices, which was a participation of their idolatry.