They did not know (Good News Translation “they did not realize what was happening”): most languages will doubtless require the explicit mention of an object after the verb know: “they knew nothing” (New English Bible) or “they suspected nothing” (New Jerusalem Bible).

Swept them all away can be rendered “carried them all away” or “destroyed them all.”

The coming of the Son of man may necessitate restructuring similar to Good News Translation: “when the Son of Man comes.”

The comparison so will be of the text is translated “That is how it will be” by Good News Translation. Some translators will find they need to reverse the order, as in “When the Son of Man comes, it will be just like that.”

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 .