He was an adversary of Israel: The Hebrew noun rendered adversary occurs also in verses 14 and 23. See the comments on this same noun in 1 Kgs 5.4.

All the days of Solomon is a literal translation of the Hebrew. Some modern versions say “as long as Solomon lived” (New American Bible, New International Version; similarly Good News Translation), but the sense in this context is more precisely “all through Solomon’s reign” (Revised English Bible, La Bible du Semeur). Since Solomon says in 1 Kgs 5.4 that he has “neither adversary nor misfortune,” some interpreters argue that the words here must therefore mean “all the remaining days of his old age” (considering that verse 4 states that Solomon turned away from God in his old age). But such a translation is not recommended, despite the apparent conflict with the statement in 5.4.

Doing mischief as Hadad did is literally “and the evil which Hadad.” Different attempts have been made by interpreters to correct the Hebrew text here. But Critique Textuelle de l’Ancien Testament correctly suggests that the Hebrew has left something out and gives a {B} rating to the Masoretic Text. The word did is understood in the Hebrew without being written. The meaning is that Rezon was an adversary “in addition to the harm which Hadad did.”

He abhorred Israel: Abhorred is the reading of the Masoretic Text, to which Critique Textuelle de l’Ancien Testament gives a {B} rating. In this context the Hebrew verb yaqats has the meaning of refusing to acknowledge authority, which leads to rebellion. This may be translated “despised” (New Revised Standard Version), “detested” (Bible en français courant), or “repudiated [the authority of]” (New Jewish Publication Society’s Tanakh). The Syriac says that he “oppressed” Israel. If the final two consonants in the Hebrew verb are reversed (yatseq), the meaning becomes “oppressed.”

Reigned over Syria: Syria (“Aram” in Hebrew; see 1 Kgs 10.29) is based on the Masoretic Text, to which Critique Textuelle de l’Ancien Testament gives a {B} rating. The Septuagint reads “Edom,” which requires a change of one consonant only in the Hebrew name. If the Masoretic Text is followed, it will be better to use the more familiar name Syria instead of “Aram” (New Jewish Publication Society’s Tanakh, New International Version). Translations following the Septuagint include La Bible Pléiade and Revised English Bible. Since Damascus was the capital of Syria, the statement that Rezon reigned over Syria may mean that he expanded his rule beyond the city to include the entire region. Compare Die Bibel im heutigen Deutsch: “Rezon became king over all of Syria.”

Regarding the second half of this verse, see the comments on verse 22. If the second part of this verse is placed at the end of verse 22, then the subject of the verbs abhorred and reigned must be Hadad, ruler of Edom.

But if the second half of this verse remains here, then the subject of these verbs is most likely Rezon, and this may be made explicit by inserting his name (so New International Version, New Living Translation). If Rezon is the subject, the reading “Aram” must be preferred over the Septuagint reading “Edom.” An American Translation, however, says that “he [Rezon] abhorred Israel and ruled over Edom.”

It may be noted that Parola Del Signore: La Bibbia in Lingua Corrente keeps the second half of this verse here but understands this to be a summary about Hadad and not additional information about Rezon. Parola Del Signore: La Bibbia in Lingua Corrente renders verse 25 as follows:

• Throughout all Solomon’s life, Rezon was an enemy of Israel.
Hadad also was against Israel and did evil. Hadad was king of Edom.

Quoted with permission from Omanson, Roger L. and Ellington, John E. A Handbook on 1-2 Kings, Volume 1. (UBS Helps for Translators). New York: UBS, 2008. For this and other handbooks for translators see here .