In the text the object, of that day and hour, precedes the subject and verb, no one knows. But this may not be natural, and most translators have “But no one knows the day and hour when that will happen” or “But no one knows exactly when all this will take place.” It may be helpful to then start a new sentence, such as “Even the angels of heaven don’t know, nor even the Son,” or possibly “Even the angels of heaven and the Son do not know the time.” Some repeat the verb: “Even the angels of heaven don’t know; even the Son does not know.”

As both Revised Standard Version and Good News Translation indicate, nor the Son is lacking in some Greek manuscripts, though the phrase is found in the best representatives of the standard text types. It is possible that the words were added on the basis of Mark 13.32, but TC-GNT believes it more probable that they were omitted “because of the doctrinal difficulty they present.” In addition, the Greek sentence structure suggests that the phrase was originally there. Nevertheless, the UBS Greek New Testament rates its decision “C,” indicating “a considerable degree of doubt” regarding what may have been the original reading. Almost all modern translations include the phrase, and some (New English Bible, New American Bible, Luther 1984) do so without even indicating the alternative possibility.

Of course, in many languages the Son cannot stand alone, and a parent must be specified. In this case “the Son of God” is probably best.

But the Father only: in the Greek text the adjective only is made emphatic by Matthew, though not by Mark. However, the difference is difficult to represent in translation, and it does not come through in Revised Standard Version, for example, which renders the Marcan parallel as “but only the Father” (13.32). Again, it may be helpful to add the verb: “but only the Father knows” or, to convey also the emphasis of the text, “but it is only the Father who knows” or “but the Father knows, and he alone.” As elsewhere in the Gospel, Father is often rendered “God the Father.”

Luke omits this verse and concludes his discourse on the last things with a passage (21.34, 36) that has no parallel in either Mark or Matthew. Mark concludes his discourse by following this verse with sayings (13.33-37) that are found in Matthew 25.14-15b; 24.42; 25.13.

Quoted with permission from Newman, Barclay M. and Stine, Philip C. A Handbook on the Gospel of Matthew. (UBS Handbook Series). New York: UBS, 1988. For this and other handbooks for translators see here .