Ronald L. Troxel, «Economic Plunder as a Leitmotif in LXX-Isaiah», Vol. 83 (2002) 375-391
The translator of LXX-Isaiah is known to have perceived in the prophet’s words presages of events in his day and to have expressed those in his translation. Some such themes recur often enough to merit designating them leitmotifs. Such is the case with the description of the people’s plunder through taxation as portrayed in 3,12-15; 5,5.17; 6,13; 9,3-4. Each of these descriptions arises through a unique construal of Hebrew syntax or an assumption of novel semantic ranges for Hebrew lexemes. The appearance of this theme in each of these otherwise unrelated passages merits designating it a leitmotif.
Thus, even if oi( dihrpasme/noi was derived by relating My#bk to #$bk, the choice of oi( dihrpasme/noi again reflects the translator’s conviction that those to benefit from the Lord’s judgment will be those who have suffered economically.
IV. Isaiah 6,13
The translator’s attraction to the motif of economic plunder, with punishment for the perpetrators, illumines a peculiar equivalence in 6,13, where he renders r(bl with ei)j pronomh/n. Even though pronomh/ in Greek literature can mean "forage", the LXX generally, and the translator of Isaiah in particular, uses it to translate Hebrew words meaning "to plunder" 44, making that the meaning of pronomh/ in this instance. Never outside Isaiah is r(b translated by a Greek word meaning "plunder", while LXX-Isa typically translates it with Greek words meaning "to burn" 45.
G’s translation seems based on contextual exegesis 46. Like the other versions, G struggles to understand the commission of vv. 9-10 47. In place of the MT’s command to impose obduracy (v. 10) stands an explanation of v. 9’s commission to futile proclamation: