en_tn/luk/12/40.md

because the Son of Man is coming at an hour that you do not expect

The similarity between a thief (Luke 12:39) and the Son of Man is that people do not know when either one will come, so they need to be ready. Jesus is not saying that he himself is a thief.

the Son of Man is coming

Jesus is talking about himself. Alternate translation: "I, the Son of Man, am coming"