In Greek the pronoun you is expressed explicitly and placed in emphatic position. This is significant because Greek does not require the explicit use of the pronoun in instances when a form of the verb indicates the subject.

The context clearly implies that be ready has the more specific meaning of “always be ready” (Good News Translation) or “be ready at any time.” New Jerusalem Bible has “stand ready,” which conveys the same impact. In some languages it is necessary to say what the disciples must be ready for. A good sentence then is “Therefore you must be ready for the Son of Man’s coming, because he will come when you do not expect him.”

At an hour you do not expect (Good News Translation “when you are not expecting him”) is the real focus of interest in the last half of the verse.

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 .