1
general::
Repeat an argument or other issue over and over, harp on something, as in We've discussed her decision? let's not belabor the point. This term dates from the mid-1900s and derives from belabor in the sense of "assail with words," a usage dating from the late 1500s.
American Heritage Idioms
2
general::
Phrase(s): belabor the point
to spend too much time on one item of discussion. • I don’t want to belabor the point, but the sooner we get this matter settled, the better. • If the speaker would agree not to belabor the point further, I will place it on the agenda for resolution at the next meeting.
McGrawhill's American Idioms And Phrasal Verbs