Beginning with this verse 17, the tree metaphor introduced in verse 16 is developed into an allegory which continues through verse 24.

Verse 17 introduces an “if” clause which is continued into the first part of verse 18 in Greek. Since the “if” clause introduces a condition which is true to fact, the Good News Translation changes it to a statement. Moreover, the metaphorical references are made clear for the reader. The wild olive tree (translated literally from the Greek) is identified as the Gentiles—you Gentiles because Paul is speaking directly to Gentile Christians (v. 13)—and “the rich root of the cultivated olive tree” is identified as the rich life of the Jews.

The cultivated olive tree may be translated as “the olive tree that people take good care of.” But in reality this refers to a grafted olive tree, that is to say, a tree formed from the roots of a wild olive tree on which have been grafted the shoots of a good olive tree. In a number of languages there are precise ways of talking about such a cultivated tree. On the other hand, wild olive tree may simply be translated as “an olive tree that grew up without being planted,” “an olive tree that grew up outside the garden,” or, more technically in some languages, “an ungrafted olive tree.”

Where the process of grafting is well known there is no difficulty in obtaining a satisfactory equivalent of the phrase joined to it. Where this is not the case, it may be necessary to use some kind of descriptive equivalent—for example, “cause to grow as a part of the cultivated olive tree” or “cause to grow just as though it were a part of the cultivated olive tree.” Because of the utter strangeness of such an activity, it may even be advisable in some languages to add some explanatory marginal note which will indicate more precisely what is involved.

It is not always easy to speak of “sharing” the strength and rich life of the Jews. In many cases a more general statement seems to be a more satisfactory equivalent—for example, “you benefit from what the Jews have made possible” or “you greatly benefit from what comes from the Jews.” The relation of the metaphor may be preserved somewhat by including it as a type of simile—for example, “you benefit from what has come from the Jews in the same way that the branch of the wild olive tree benefits from the sap of the cultivated olive tree.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .