Mark 13:33-36

Take heed, watch and pray; for you do not know when the time is. It is like a man going to a far country, who left his house and gave authority to his servants, and to each his work, and commanded the doorkeeper to watch. Watch therefore, for you do not know when the master of the house is coming—in the evening, at midnight, at the crowing of the rooster, or in the morning— lest, coming suddenly, he find you sleeping.