See 1 Kings 5:15 note.

A tribute of bond-service - He made them do the most laborious part of the public works, the Israelites being generally exempt. When Sesostris, king of Egypt, returned from his wars, he caused temples to be built in all the cities of Egypt, but did not employ one Egyptian in the work, having built the whole by the hands of the captives which he had taken in his wars. Hence he caused this inscription to be placed upon each temple: -

Ουδεις εγχωριος εις αυτα μεμοχθηκε.

No native has labored in these

Diodor. Sic. Bibl., lib. i., c. 56.

It appears that Solomon might with propriety have placed a similar inscription on most of his works.

Their children that were left after them in the land,.... The posterity of those left unsubdued in the times of Joshua:

whom the children of Israel also were not able utterly to destroy; in later times, though now it is thought by some it was not for want of power, but because they had made a covenant with them, as the Gibeonites did, and therefore they could not, because it would have been a breach of covenant to have destroyed them; see 2 Chronicles 8:8,

upon these did Solomon levy a tribute of bond service unto this day; not a tribute of money, which being poor they were not able to pay, but of service, and which being once laid on was continued, and even to the time of the writing of this book.

Their children that were left after them in the land, whom the children of Israel also were not able utterly to destroy, upon those did Solomon levy a tribute of bondservice unto this day.

9:21 Those - He used them as bondmen, and imposed bodily labours upon them. But why did not Solomon destroy them as God had commanded, when now it was fully in his power to do so? The command of destroying them, Deut 7:2, did chiefly, if not only, concern that generation of Canaanites, who lived in, or, near the time of the Israelites entering into Canaan. And that command seems not to be absolute, but conditional, and with some exception for those who should submit and embrace the true religion, as may be gathered both from Josh 11:19, and from the history of the Gibeonites. For if God's command had been absolute, the oaths of Joshua, and of the princes, could not have obliged them, nor dispensed with such a command.

9:15-28 Here is a further account of Solomon's greatness. He began at the right end, for he built God's house first, and finished that before he began his own; then God blessed him, and he prospered in all his other buildings. Let piety begin, and profit follow; leave pleasure to the last. Whatever pains we take for the glory of God, and to profit others, we are likely to have the advantage. Canaan, the holy land, the glory of all lands, had no gold in it; which shows that the best produce is that which is for the present support of life, our own and others; such things did Canaan produce. Solomon got much by his merchandise, and yet has directed us to a better trade, within reach of the poorest. Wisdom is better than the merchandise of silver, and the gain thereof than fine gold, Pr 3:14.