The phrase As long as it is day, which must be understood figuratively, in general should be placed close to the expression of “doing.” It may be better to place it at the beginning of the sentence, for example, “as long as it is day, we must keep on doing the works of him who sent me.” Otherwise, the reader might understand it as a qualification of him who sent me.

In Greek an impersonal construction (literally “it is necessary for us to do”) is used, which Good News Translation transforms into a more natural English expression (We must do).

In place of the first person plural we, some manuscripts have the singular “I,” while in the latter half of the verse some Greek manuscripts read “us” in place of me. Good News Translation accepts the reading we because it has the best manuscript support, and because, since Jesus is the speaker, it is more likely that a scribe would change the plural we to the singular “I” than the other way around. The reading “us” is supported by good manuscript evidence, but the UBS Committee on the Greek text suggests that the translator follow the reading me on the assumption that “us” was introduced into the manuscripts in order to conform with we in the first part of the verse. Moffatt, Revised Standard Version, Phillips, New American Bible, and New English Bible all follow the same text as Good News Translation; Jerusalem Bible, La Sainte Bible: Nouvelle version Segond révisée, Die Bibel im heutigen Deutsch, and Luther accept the reading of the first person singular in both places (“I … me”). The choice of text is not easy, and the UBS Committee has rated its decision “C,” indicating considerable doubt concerning the reading selected.

Him who sent me clearly refers to God; see Die Bibel im heutigen Deutsch “I must accomplish the works for which God has sent me.”

It may not be easy to reproduce effectively the meaning of the clause we must do the work of him who sent me. Work refers, of course, to miracles, or “only such works as God himself can do.” It may be possible in some languages to translate “We must keep on doing such wonderful works as only God who sent me can do” or “We must keep on doing what the one who sent me ordered me to do.”

Night is coming, when no one can work may be rendered in some languages “It will soon be night, and then no one can work.” Such a modification must be introduced in languages in which one cannot speak of night “coming.” It is also necessary in this type of context to avoid a term for work which would mean only physical labour. Thus the final clause of the verse may be translated “then no one will be able to do anything.”

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 .