I have sworn by myself, the word is gone out of my mouth in righteousness, and shall not return, That unto me every knee shall bow, every tongue shall swear. I have sworn by myself - במימרי bemeymri, by my Word: and the word - פתגם pithgam, or saying, to distinguish it from the personal substantial Word meymra, mentioned before. See the Targum.
The word is gone out of my mouth "Truth is gone forth from my mouth; the word" - So the Septuagint distinguish the members of the sentence, preserving the elegance of the construction and the clearness of the sense.