In this context the word prophet has the specific meaning of “one who sees and foretells the future.” As noted in the section on the discourse structure, there is a shift in temporal sequence from verses 29b to 30. Verse 29b contains a reference to David’s death, while verse 30 describes what David did while still alive. In some languages verse 30 must begin with an explicit reference to this shift in time, for example, “While David was still living, he was a prophet” or “David had been a prophet.”
In the Greek text the reference to the oath comes directly after the verbal form knew, but in the Good News Translation the rather full expression “to swear by means of an oath” is reproduced as promise … made a vow. Note, however, that in the Good News Translation the promise is the fact that God would make one of David’s descendants a king; it is not that God would make a vow.
In most languages an expression for “swearing” or “promising by means of an oath” is not difficult to find or to employ in this type of context, but where such formal oath-taking is not normally practiced one may need to employ some substitute type of expression which will communicate the essential components of the Greek terms, for example, “he made a strong promise to him” or “he promised David with powerful words.” In many other contexts one can translate “to make an oath” as “to promise, calling God to witness,” but since in this context it is God who makes the oath, such a phrase, designed to indicate the religious nature of the promise, cannot be employed.
The expression make … a king may be rendered as “would cause … to become a king.” Two Semitic idioms are translated in the Good News Translation expression one of David’s descendants (literally “from the fruit of his loins”) and a king, just as David was (literally “to sit upon his throne”). The second of these idioms is easily understood; and so is the first when it is realized that “loins” was often used by the Hebrews to specify the reproductive organs. The passage referred to is Psalm 132.11.
It is obviously necessary in most languages to modify the idiom “fruit of his loins,” but even a general term for descendant is not easy to find in some languages. So many kinship terms are entirely too specific. However, one can often use such phrases as “distant grandchild” or “grandchild much later.” Other acceptable solutions may be “a man in David’s lineage” or “a later man in David’s family,” in which “lineage” and “family” must be terms to indicate a relatively long succession.
The term king differs from other words for “ruler” simply by virtue of the fact that there is a succession of leadership from father to son. In some societies, however, this type of succession is quite unknown, and therefore it may be necessary to translate king merely as “a great chief” or “a big chief.” A note in the margin or glossary may indicate that in ancient Israel it was the practice for a son to succeed his father as the ruler of the people.
The idiom “to sit on the throne” must usually be altered, for it may only mean the occupation of a big chair. However, if one wishes to retain the term “throne,” then it may be useful to employ an attributive, “the seat for ruling”, for example, “occupy a seat for ruling just as David did.” However, in many languages the most appropriate equivalent is “rule as David ruled.”
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 .