Matthew 24:50

on a day when he is not expecting him, and at an hour which he does not know, the Master of that servant will arrive

Matthew 24:42-44

Keep guard then, for you do not know the day on which your Master is coming.

1 Thessalonians 5:2-3

You yourselves know perfectly that the Day of the Lord will come as a thief in the night.

Revelation 3:3

Call to mind, then, what you have received and heard, and hold to it, and repent. Unless you are on the watch, I will come as a thief, and you will never know at what hour I am coming upon you.

Treasury of Scripture Knowledge

Summary

The lord of that servant shall come in a day when he looketh not for him, and in an hour that he is not aware of,

Bible References

Come

Matthew 24:42
Keep guard then, for you do not know the day on which your Master is coming.
1 Thessalonians 5:2
You yourselves know perfectly that the Day of the Lord will come as a thief in the night.
Revelation 3:3
Call to mind, then, what you have received and heard, and hold to it, and repent. Unless you are on the watch, I will come as a thief, and you will never know at what hour I am coming upon you.