The verse before us now repeats the geographical extent of Solomon’s reign, but it also adds some information. Previously we were told that other nations (and their kings) paid tribute to Solomon. Here we learn that he literally ruled over them. The Hebrew root is the word radach, which means to have dominion, to rule.
Solomon, in truth, had an empire over which he exercised sovereign authority.
An independent nation could pay tribute to a foreign monarch while still retaining much of its sovereignty. As long as the tribute flowed to the overlord, the rulers of the tributary states could see to their own affairs.
We must understand that the kings mentioned here were what we might call puppet kings. They were subject, not only to Solomon’s taxation but also to his commands. He was king over other kings.
24 Il dominait sur tout le pays de l'autre côté du fleuve, depuis Thiphsach jusqu'à Gaza, sur tous les rois de l'autre côté du fleuve. Et il avait la paix de tous les côtés.