And Isaac came - Concerning this well see Gen 16:13, Gen 16:14, etc. As it appears from Gen 25:11, that Isaac dwelt at the well Lahai-roi, it has been conjectured that he had now come on a visit to his aged father at Beersheba, where he waited in expectation of his bride.
For he dwelt in the south country - The southern part of the land of Canaan. See Gen 12:9.