וַיִּסַּ֨ע מִשָּׁ֤ם אַבְרָהָם֙ אַ֣רְצָה הַנֶּ֔גֶב וַיֵּ֥שֶׁב בֵּין־קָדֵ֖שׁ וּבֵ֣ין שׁ֑וּר וַיָּ֖גָר בִּגְרָֽר׃
און אבֿרהם האָט אַװעקגעצױגן פֿון דאָרטן צום לאַנד פֿון דרום, און ער האָט זיך באַזעצט צװישן קָדֵש און צװישן שור, און האָט געװױנט אין גרָר.
Rashi
ויסע משם אברהם AND ABRAHAM JOURNEYED FROM THENCE—When he observed that the cities had been destroyed and travellers ceased to pass to and fro, he went away from there. Another explanation is: he journeyed from there to get away from Lot who had gained an evil reputation because of his intercourse with his daughters (Genesis Rabbah 52:3-4).
Chizkuni
ויסע משם, “he moved away from there.” He moved away from Eloney Mamre.
Sforno
וישב בין קדש ובי שור, between 2 large cities, in order to have an opportunity to proclaim the holy name of G’d in both these cities, as he did later, the objective being to improve G’d’s image among mankind.