You also must be prepared. For the Son of man will return at an hour that you will not realize.
Other versions
King James Version
Be ye therefore ready also: for the Son of man cometh at an hour when ye think not.English Standard Version
You also must be ready, for the Son of Man is coming at an hour you do not expect."New International Version
You also must be ready, because the Son of Man will come at an hour when you do not expect him."