The classical source expands or derives a specific point from the language of the passuk. The Core Text above is the relevant region of interest.
Type of Learning
Custom (A positive derivation from the shared language of “arur” and “kelalah”: the term “arur” itself functions as a form of curse.)
What Is Learned
Wherever the Torah or a person employs the language of “arur,” it carries the force of a curse. One who curses himself, his fellow, or the Nasi with the word “arur” is therefore liable just as for an explicit kelalah.