(I'll) be seeing you
Goodbye; see you soon. Have a safe trip. I'll be seeing you. A: "Thanks for such a fun night! See you later!" B: "Be seeing you!"
I'll be seeing you
Also, see you. Goodbye, as in I have to go now; I'll be seeing you, or All right, see you. These colloquial formulas do not necessarily imply a future meeting. [Late 1800s]