Bereshit 13:11

ככר The word means “a plain” as the Targum translates it. מקדם FROM THE EAST — He removed from Abram and went westward of Abram — consequently he travelled from the East to the West. A Midrashic explanation is: He wandered away from the Originator (מקדמונו) of the Universe, saying, “I want neither Abram nor his God” (Genesis Rabbah 41:7).

וַיִּבְחַר־ל֣וֹ ל֗וֹט אֵ֚ת כׇּל־כִּכַּ֣ר הַיַּרְדֵּ֔ן וַיִּסַּ֥ע ל֖וֹט מִקֶּ֑דֶם וַיִּפָּ֣רְד֔וּ אִ֖ישׁ מֵעַ֥ל אָחִֽיו׃

Then Lot chose him all the plain of the Yarden; and Lot journeyed east; and they separated themselves one from the other.