John Gill Commentary 1 Samuel 15:7

"And Saul smote the Amalekites, from Havilah as thou goest to Shur, that is before Egypt." — 1 Samuel 15:7 (ASV)

And Saul smote the Amalekites
Engaging in battle with them, he overcame them, and beat them, and slew great numbers of them:

from Havilah until you come to Shur, that is over against Egypt ;
having routed them in the valley, or in whatever place the battle was fought, he pursued them from one end of their country to the other; from Havilah, which lay to the northeast, to Shur, which lay to the southwest, and destroyed all that came in his way between those two points, see (Genesis 25:18) .