This verse contains several more difficulties. The speaker is the LORD.
My spirit translates the Hebrew ruach, which has been interpreted in various ways; for example, as the spiritual existence of God as contrasted with the flesh of human beings, as the life principle, as the ethical principle, and as the divine spirit common to God and to the “sons of God.” A number of modern translations use something like “breath,” “spirit,” or “Spirit,” and some of these take the term to refer to Gen 2.7, in which “the LORD formed man of dust … and breathed into his nostrils the breath of life.” In this sense My spirit means “the power that gives life”; this leads New English Bible to describe spirit and say “my life-giving spirit.” A good way to translate here is, for example, “My spirit that causes people to live,” “My power to cause people to live,” “My life-giving power,” or “My power that creates life.” One recent translation makes this a separate sentence at the beginning of the verse: “I put my spirit into people to give them life. Now I will not….” Another simply says “It is not good that I allow my life to remain in people for ever,” with a footnote giving the literal rendering “spirit.” Other modern translations take My spirit to simply be a way of saying “I.”
Shall not abide translates a word that occurs nowhere else in the Old Testament, and so its meaning is somewhat uncertain. Abide and “remain” have been used traditionally and seem to fit the context well. Note how translations that use “I” in place of My spirit restructure this clause; for example, Good News Translation and Biblia Dios Habla Hoy have “I will not allow people to live forever,” Bible en français courant “I cannot allow people to take advantage indefinitely of the breath of life that I gave them.”
The term flesh is in this case a reference to human nature, and in particular to the fact that human life comes to an end in death. This is well expressed in English by Good News Translation and others with the use of the term “mortal.” We may also say, for example, “They are only people who live and then die” or “He is nothing more than a human being who will die.” In a number of languages the meaning of flesh is expressed in a phrase that says literally “belonging to the world” or “beings of the world.” One recent translation says “They are only beings of the world who will [inevitably] die.”
But marks a contrast between the life span granted by God to people in the past, and the life span that is to apply in the future; and so Revised Standard Version but may be rendered better as in Good News Translation, “From now on,” or else “Beginning now,” or “In the future.”
His days refers to the life span of people, as in 3.14, 17. Days is used idiomatically here and should not be used in translation, unless its sense is equivalent to “length of life,” “total number of years.” Some languages, of course, do have idioms similar to that in Hebrew, such as “their days of life.”
The whole expression his days shall be a hundred and twenty years will often need to be restructured. In particular, translators may need to bring out the element of “only 120 years,” since this period of time is actually a new limitation, even though it will seem like a very long life span for readers today. Some examples from existing translations are “From now on they will receive only 120 years,” “Their days of life will be equal to just 120 years,” and “I will let them live for only 120 years, then they will die.”
A hundred and twenty years can hardly be taken literally, since Noah goes on to live to the age of 950, and in chapter 11 Noah’s descendants are also said to have lived far in excess of 120 years. Two main views have been held regarding this figure: (1) that 120 years represents a time of grace given by God for all people to repent before the flood; and (2) that in the future a person’s life span will be 120 years, in which case there would be many exceptions, as in 11.10-26, or else the declining length of years in 11.10-26 shows a gradual adjustment toward 120 years. See also Psa 90.10.
As pointed out at the opening of this subdivision, these passages are at best obscure. But regardless of how 120 years is to be related to the context, the translator has to render this number as it is.
Quoted with permission from Reyburn, William D. and Fry, Euan McG. A Handbook on Genesis. (UBS Helps for Translators). New York: UBS, 1997. For this and other handbooks for translators see here .