EXTRA · Parashas Vayeira · Passuk 21:31
Supplementary classical material; Torah Temimah lists no citation under this passuk.
Therefore that place was called Be’er Sheva, because there the two of them swore an oath.
Rashi on Genesis 21:30–31 (naming and the seven ewes as testimony).
Sefaria — Rashi on Genesis 21:30
English: “So that it may be a witness for me” — the feminine form of “testimony.” Therefore the place was called Be’er Sheva — on account of the oath and on account of the seven ewes.
Derash on the verse (Rashi) — not a formal named middah of the 13. Place-name is grounded in both the oath and the numerical gift.
A place-name can encode both legal testimony and the act of swearing; Be’er Sheva remembers the well, the seven, and the mutual oath.