1 Kings 3:1

Some wonder why Solomon made alliances with the Gentiles through marriages without being blamed, even though [the Law] forbade [the Hebrews] mixing with them. The reason for that prohibition was "lest" [the Scripture says], "[their daughters] might make your sons also prostitute themselves to their gods." And this is what happened to Solomon as well. However, we also see others who married daughters of the Gentiles, but since they were not seduced to follow their paganism, they were filled with praises: for instance, Mahlon, Chilion and Boaz. With regard to Solomon, since he thought he would avert his people from war and establish a house for the Lord through his connections with the foreign kings, for this reason he married their daughters, and not out of lust; therefore he was not blamed for this. But after he fell into the error of their idolatry—that is, he did not correct [his women] from their error—he was blamed by God.