Bible translations and footnotes

The starting point in answering your question is recognizing that none of the original manuscripts of the Bible are extant today.  What we have are copies of copies of copies.  That hand copying of biblical manuscripts over the centuries was extremely accurate, but variants—different words or word forms—exist among the manuscripts.  The variants in the New Testament manuscripts that require attention from those who have biblical language training amount to less than one percent of the text.  And, most importantly, no doctrine of the Bible is uncertain because of variants among manuscripts.

When Bible scholars and Bible translators come upon a passage where ancient manuscripts might differ, as in Mark 7:16, their rule of thumb is to side with the oldest and most widespread manuscripts because they would most likely reflect the content of the original manuscripts.  In the case of the Bible translations you cited, their footnoting of verses not in the text or their footnoting of alternate translations reflects the careful study given to variants and the judgment calls that need to be made.

The subject matter of your question requires a much lengthier answer than I can provide on this forum.  This link will offer you a much longer explanation of “Verbal Inspiration and the Variant Readings.”

When we keep the subject matter of variants in perspective, we can acknowledge—with gratitude and awe—that God has preserved his word to this day.  That is no surprise.  “The grass withers and the flowers fall, but the word of our God stands forever” (Isaiah 40:8).