וַיַּ֣ךְ דָּוִ֔ד אֶת־הֲדַדְעֶ֥זֶר בֶּן־רְחֹ֖ב מֶ֣לֶךְ צוֹבָ֑ה בְּלֶכְתּ֕וֹ לְהָשִׁ֥יב יָד֖וֹ בִּֽנְהַר־[פְּרָֽת׃]
David schlug auch den Hadadeser, Sohn Rehobs, König von Zoba, als er ihm am Euphrat entgegentreten wollte.
Chizkuni
יד, the word יד normally translated as “hand,” in this instance refers to power, Royal authority.” We know of a similar example for the meaning of that word from Samuel I 15,12, where the prophet Shmuel was advised of Shaul’s arriving at Mount Carmel, and he prepares for this by erecting a יד, for him, i.e. an altar. The words there are: והנה הוא מציב לו יד. In Samuel II 8,3 we also find the word יד used in this sense when David built an altar. [Not the traditional understanding of the word by most commentators. Ed.] The word כסא usually is used as a symbol of power, Royal Power.[If this is so, the word יד in the same line cannot mean the same, of course. Ed.] A different interpretation: the verse means that as long as nations, or especially Amalek, see in Jerusalem and what its stands for its spiritual nemesis, there will be an ongoing war between G-d and His representative on earth, Israel; מלחמה לה' בעמלק, “a state of war between G-d and Amalek; this phrase is what the liturgist has in mind when he wrote in his poetic prayer recited on the Sabbath preceding the reading of Parshat zachor on the Sabbath preceding Purim.־, commencing with the words: אלוקים אל דמי לך, “do not be silent o G-d”; the author queries G-d’s relative inactivity versus Amalek although He has dealt more harshly with other adversaries throughout history. [There are only few congregations in which this liturgical poem is recited nowadays in the synagogues. It is lengthy and the language requires assistance by commentaries as provided in the prayer book known as otzar hatefillot. Ed.] G-d’s answer is that until Amalek attacks G-d directly, not just His people, it is our task to deal with him, once he does the latter, G-d personally will wipe him out, This is why when Titus destroyed the Temple in Jerusalem G-d dealt with him, whereas at this stage it was our task to fight him. According to Jeremiah 3,17 Jerusalem is called G-d’s throne.