se.phar is used as the proper name marking the eastern endpoint of a dwelling’s extent.

The attested use is a proper name in a geographic boundary statement: Genesis 10:30 places it at the eastern end of the described dwelling area.

1. Proper name at an eastern boundary · dominant

   In Genesis 10:30, the form is tagged Noun · Proper and occurs in the clause marking the dwelling "from Mesha as one comes to Sephar"; the APB then identifies it as "the mountain of the East."

   Genesis 10:30

In the Anselm Project Bible: In Genesis 10:30, the APB presents the name in the boundary phrase "as one comes to Sephar" and adds "the mountain of the East."