Matthew 24:43-44

24:43 But understand this: If the owner of the house had known at what time of night the thief ¹  was coming, he would have been alert and would not have let his house be broken into. 24:44 Therefore you also must be ready, because the Son of Man will come at an hour when you do not expect him. ² 

¹ sn On Jesus pictured as a returning thief, see 1 Thess 5:2, 4; 2 Pet 3:10; Rev 3:3; 16:15.

² sn Jesus made clear that his coming could not be timed, and suggested it would take some time – so long, in fact, that some will not be looking for him any longer (at an hour when you do not expect him).