D. Charles Pyle discusses the potential Egyptian words informing "eternity" and "everlasting" in the Book of Mormon.
D. Charles Pyle, I Have Said Ye Are Gods: Concepts Conducive to the Early Christian Doctrine of Deification in Patristic Literature and the Underlying Strata of the Greek New Testament (Revised and Supplemented) (North Charleston, S.C.: CreateSpace, 2018), 225-28
In any case, as can be seen, the Bible’s wording does not actually mean any such thing as critics claim. But what of the Book of Mormon and its use therein of such “everlasting to everlasting” and “all eternity to all eternity” phrases? Since the Book of Mormon was written in Egyptian, how does that come into play? Are the meanings similar to those found in the Bible, and if so, however/ part of the answer lies in the fact that not only was the Book of Mormon originally composed in Egyptian, but that this Egyptian language also was written with he learning of the Jews. Nephi so states that he did. It is not a stretch to believe that the others did the same with whatever cultural knowledge they might then have had. In the time of Moroni both Hebrew and Egyptian were known to Moroni, though the characters (and likely elements) of the languages were modified somewhat. The point is that while they were writing in Egyptian they very likely were thinking in Hebrew, and they thus would have had that Hebraic way of thinking in mind while writing. Understanding that as well as knowing the large number of differences between Egyptian and Hebrew, Moroni had worked himself up into a worry that he would not adequately make his points come across without someone someday mocking what he had written. Therefore, whenever we come across passages that speak of someone or something being “from everlasting to everlasting” or “from all eternity to all eternity” in the Book of Mormon, it is very likely would have had the same meanings as the phrases in Hebrew.
It not even is necessary here to quote passages herein to discuss them in the light of the above since they are of so little use to critics now that we have discussed all of the above from only the texts of the Bible, because they relate to the Book of Mormon. Some critics may well be quick to hump at this and say, “Not so fast! You cannot get around this when your own Book of Mormon says ‘all eternity’ in its own passages!” Such passages critics might use may be any of the following: Mosiah 3:5; Alma 13:7; Moroni 7:22 or Moroni 8:18. To such questioning the author might then respond, “Wasn’t Psalms 145:13 example enough that even ‘all eternity’ may not actually mean what people think it might mean in the text???” For the wise that should be enough, but there is more. The words for “all” in the Bible often carry an exaggerative, emphatic sense, both in Greek (under the influence of Hebrew and Aramaic) and in Hebrew. A more detailed discussion concerning this tendency will be seen on pages 309-313 below.
We simply could end here on this point of the Nephites thinking in terms of Hebrew meanings when composing in Egyptian words and sentences, but it also is of interest to note what ancient Egyptians would have expressed if the Nephites themselves also thought similarly to the way that the Egyptian people did while writing their own religious and other texts in Egyptian. For instance, the Egyptian word for eternity, ḥḥ, was expressed both by the word as well as by the ideographic symbol of the same meaning, both of which had the same range of meaning from “a great but indefinite number” to “millions” (as in the number of years, also seen in some writings) in their religious texts. A deity named Ḥḥ was in their pantheon, with the tacit understanding among the ancient Egyptians that this god thus himself was also “the god of hundreds of thousands of years.” Another way of writing the word was nḥḥ (meaning eternity). And in connection with the word’s form there also was a deity named Nḥḥ (described as “the god of eternity”).
The Egyptians, much as the Hebrews so did, sometimes also would string together words expressing long durations of time. Yet even those usages still represented long, measurable durations of time, thus demonstrating that even the Egyptians used various words (which frequently are translated as eternity, everlasting, and for ever and ever) similarly to how the Egyptians also did with respect to time. For instance, they might want to write a phrase like nḥḥ dt (or its fuller form nḥḥ ḥn’dt) to mean something like eternity with everlastingness. Thus, Egyptian also used similar approaches to meaning in which words were attached to other words, as also seen in the use of the phrase ḥḥ nn dr, or its fuller form ḥḥ nn dr’ (meaning literally millions of years without limit, or an eternity without end). The mere existence of such constructions show us that even Egyptian ḥḥ and nḥḥ did not mean eternity as we have tended to think of the concept. Now did dt by itself meaning everlasting as we might assume it did. Also weighty is evidence we have sense than an Egyptian word for eternity in a phrase like ḥtr šn nḥḥ (meaning a tax fixed for ever or a perpetual tax) also reveals to us that said word did not have inherent within it a meaning we might want to attach to it with our Western way of looking at philosophical constructs.
As we have seen above, this is just what the Hebrews did with their own words for long durations of time. As we now can see, regardless of whether the Book of Mormon authors used the Egyptian language with the learning of the Jews, or, Hebrew expressed in Egyptian characters, it makes little to no difference. The occurrences of “everlasting to everlasting” or “all eternity to all eternity” phrases in the Book of Mormon are not as useful to the critics as they’ve imagined them to be.