The Septuagint was done by 6 scribes from each tribe of Israel.
Which, people should be aware of, is a legend began by Aristeas. As you know 6 x 12 is 72, but there's an older legend based on Exodus 24:1-9 where 70 elders went with Moses to receive the tablets from Yahweh. So it makes sense that the first translation into Greek (which technically should only be applied to the Greek Pentateuch)should be carried out by 70 elders.
They would have used the best available copies of the day as is bore out by the DSS.
Which contradicts the fact that the Septuagint was one of the poorest translations of the OT known to man!
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