The two phrases every branch … and every branch … are emphatic in the Greek sentence structure. The word rendered branch in this verse does not appear elsewhere in the New Testament. It is specifically used of vine branches, though it may also be used of other branches as well.

Some scholars contend that the Greek term translated vine really means “vine stalk,” and that the vine stalk must be clearly distinguished from the branches. However, most exegetes understand this term to include both stalk and branches, since the branches can be regarded as part of the vine, in the same way that believers may be regarded as part of Christ; that is, they are in him even as he is in them.

Every branch in me must be rendered in some languages “every branch that is a part of me” or “every branch that is attached to me.” However, if it is necessary to explain the relation of in me by a separate clause, the structure may become relatively complex, for example, “He breaks off every branch that is a part of me that does not bear fruit.” This type of structure is often impossible in translation. In some languages therefore it may be better to employ a conditional construction, for example, “If a branch that is a part of me does not bear fruit, he breaks it off.”

The verb translated breaks off literally means “to take away,” while the verb rendered prunes … so that it will be clean literally means “to cleanse,” and occurs only here in the New Testament. In the present context the meaning is obviously “to make clean by pruning,” which is the basis for the Good News Translation rendering. Some translators render “to clean” (see New English Bible, Moffatt), while others have “to prune” (Jerusalem Bible, Revised Standard Version). New American Bible (“prunes away … trims clean”) is essentially the same as Good News Translation. To render as Good News Translation and New American Bible do has two advantages: (1) It identifies the cleansing specifically as pruning, which is the meaning here; and (2) it brings out the idea of “to make clean,” which is important in the present verse, since there is an obvious play on the verb “to make clean” of this verse and the adjective “clean” of verse 3. The entire phrase prunes … so that it will be clean and bear more fruit is literally “cleans … in order that it may bear more fruit.”

The figurative meaning in the term prunes is difficult for many people to understand, for pruning is not a common practice in many parts of the world. Where it is practiced, it may be of quite a different type from that employed in the Middle East. The pruning to which this verse refers consists of cutting back individual branches so that the tree will produce better fruit. However, in many parts of the tropics, pruning is employed to reduce the number of branches, and thus give the remaining branches an opportunity to produce better fruit, as, for example, in pruning coffee trees. There are also difficulties in finding a term for “pruning.” It may be necessary to use a descriptive phrase, for example, “to cut the branch short,” “to cut the branch back,” or “to cut off part of the branch.”

There are also difficulties in relating pruning to a cleansing process, for pruning seems to have nothing to do with making something clean. A close approximation to this meaning may be obtained in some languages by rendering “so that it will be better and thus bear more fruit.” This type of translation may be necessary in languages in which there is no relation between physical cleanliness and spiritual holiness. However, a serious difficulty may result from eliminating such a term as “clean” since the meaning of verse 2 must be preparatory for verse 3, in which the application must be made to persons rather than the branches of a vine. In some languages, therefore, instead of using “clean”, translators employ a more general expression, for example, “prepared” or “properly prepared.” This expression may be satisfactory in both verse 2 and verse 3.

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on the Gospel of John. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .