The pronoun this at the beginning of verse 17 must be related to what follows; in fact, it stands for the following direct quotation. For many languages the first line of verse 17 must undergo considerable change of order, for example, “God says, This is what I will do in the last days,” or “In the last days I will do this” (that is, the following).

In the last days is a typical Jewish expression used to describe the time of the Messianic age in which God would fully accomplish those promises that he had made to his people. It was taken over by the first Christians and applied to the period that began when Jesus came into the world, especially from the time of his resurrection onward. It is quite significant that these words are not in the Hebrew or Greek texts of Joel but are supplied by Peter.

An expression for last days is often not easy to find. In fact, it is entirely too easy to adopt some expression which is entirely wrong, for example, “in the most recent days,” or “in the days that have just passed.” The real focus of meaning is “the days just before the end,” or as in some instances “the days just before the new time,” or “the days just before the new age.”

I will pour out my Spirit is literally “I will pour out of my Spirit” (see King James Version; Phillips “forth of my Spirit”; New English Bible “a portion of my spirit”). What Peter means by the use of this phrase is obvious: God will let all people share in his Spirit. So it seems best to translate as Good News Translation and most other translations have done. In many languages, however, one cannot “pour out Spirit,” since “Spirit” is not regarded as a mass. In such instances one may “give my Spirit to” or “cause my Spirit to come to.”

Upon all men is literally “upon all flesh,” a Semitic idiom meaning “all mankind.” In the biblical setting to prophesy primarily means to “proclaim God’s message to men,” rendered in some languages as “they will say to people, This is what God says, ….” However, in certain contexts this term refers to foretelling the future.

To see visions and to dream dreams are in biblical thought ways of receiving divine revelation. In many languages it is not easy to distinguish between visions and dreams. Technically, visions occur in trancelike states in which people are not regarded as asleep, while dreams are related to the state of sleep. In other cultures, however, any vision or dream which has some supernatural significance, that is, which involves a message from the spirit world, is identified by a single term. When there is only one term, it is possible to combine the subjects “your young men and your old men will…”

Since in this context visions and dreams are spoken of only as vehicles for the communication of divine truth, one must sometimes make the reference more explicit, since visions and dreams as such may convey no reference to the revelation involved. Hence, one can have, “your young men will see truth from God in visions and your old men will know about the truth from God through their dreams.”

In societies where terms for age-grading are very specific, the term for young men can refer to young men before marriage and the term for old men can most appropriately refer to men who are the respected leaders—the type of men who make up the group of older counselors of the chief. Of course, insofar as possible, one should avoid expressions which are too specific.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on The Acts of the Apostles. (UBS Handbook Series). New York: UBS, 1972. For this and other handbooks for translators see here .