Luke 12:39
And this know, that if the goodman of the house had known what hour the thief would come, he would have watched, and not have suffered his house to be broken through.
Cross-references
Matthew 24:43 contains the identical illustration of a thief coming unexpectedly — directly parallel saying about being ready.
In Matthew 24:44, Jesus gives the same warning to be ready because the Son of Man comes unexpectedly, reinforcing the parable's lesson.
In 1 Thessalonians 5:2, Paul uses the same thief-in-the-night metaphor for the Day of the Lord, directly echoing Jesus' teaching.
In 2 Peter 3:10, the Day of the Lord comes like a thief, using identical imagery for eschatological suddenness.
In Revelation 3:3, Jesus warns the church in Sardis that he will come like a thief if they do not wake up, applying the same metaphor.
In Revelation 16:15, Jesus again says he comes like a thief, blessing those who stay awake, paralleling Luke's call to vigilance.