Dr. Paul E. Kahle writes: “We now know that the Greek Bible text [the Septuagint] as far as it was written by Jews for Jews did not translate the Divine name by kyʹrios [Lord], but the Tetragrammaton written with Hebrew or Greek letters was retained in such MSS [manuscripts].”​—The Cairo Geniza, pages 222, 224.

Thus Dr. Kahle writes: “It was the Christians who replaced the Tetragrammaton by kyʹrios [Lord], when the divine name written in Hebrew letters was not understood any more.”​—The Cairo Geniza, page 224.