JHVH
The Doctrine of The Ineffable Name
Part 1
No written documents concerning it have been found predating the compilation of the Masoretic Bible. For it was only after the creation of the Masoretic Bible that the Tetragrammaton could be compared with the On/Kyrios of the LXX. Thus, The Doctrine of The Ineffable Name was nothing more than an apologetic expedient, fabricated by the Masoretes to justify the discrepancy between the two names and, incidentally, ignorance of the original one.
Hezekiah's seal?
If the Hebrew Bible was truly the source for the LXX, the Greeks would have synchronized Hezekiah with Sethos and Sennacherib, since we were informed by Herodotus (c. 480 BC) that these last two were contemporaries; and the Jewish Book of Kings relate how Judah was invaded by Sennacherib during the reign of Hezekiah (2 Ki. 18:13 - 19:37). So why didn't the Greeks synchronize the three? Because at the time of the LXX's composition no such person as a 'Judaic King' Hezekiah had existed! Hecataeus (c. 320 BC), whose 'Digression on the Jews' is credited with containing the first extra-biblical reference to Moses as a law-giver to a colony of Jews, not only states that Moses actually made it to Canaan and founded Jerusalem, but also that these Jews NEVER HAD KINGS, ONLY PRIESTS (re: Ex. 14:6). In addition to this, anyone who's familiar with the Book of Kings, as well as the fallacious account of the "making" of the Greek version of Hebrew scripture, knows that Ten Tribes were lost during the so-called Babylonian Captivity, thus making it IMPOSSIBLE that they would have representatives from those Lost Tribes taking part in the translation! Even as late as the days of Clement of Alexandria (c. 150 AD - c. 215 AD), mention is still being made of the "6 translators from each of the 12 tribes". Finally, If the above image is indeed a specimen of Hezekiah's seal, surely curiosity would be piqued as to why it contains symbols that are unmistakably Egyptian!