Komentarz do Diwrej ha-jamim I 18:3

And David smote Hadadezer, king of Zobah, in Hamath The war took place in Hamath, and in Hamath David smote them.

in Hamath - Heb. חֲמָתָה, like לְחַמָת, to Hamath.

to establish his power Its meaning is: when he went to establish his power, to restore his boundary and to establish it by the Euphrates River, for he was restoring to the boundary (sic) of the Euphrates River. An example is (Sam. II 18:18): “And Absalom took and established for himself in his lifetime, etc., and he called it Yad Absalom,” meaning the power of the boundary of Absalom. Another explanation of, “and he called it Yad Absalom”: Absalom engraved the form of the length of his hand in the middle of the monument, as it is written in that verse, that he said that this engraving was engraved after the shape of Absalom’s hand. (I heard this from Isaac the son of Rabbi Samuel in Narbonne.)