Another interpretation: "And he called" (Genesis 12:8) means he began to make converts. "And Abram journeyed, going on still toward the Negev" (Genesis 12:9): he kept measuring out his way and directing himself opposite the site of the Holy Temple.
Abraham Journeys Aligned Toward the Temple Site
Yalkut Shimoni on Torah 67:2
דָּבָר אַחֵר, וַיִּקְרָא, הִתְחִיל מְגַיֵּר. (בראשית יב ט) וַיִּסַּע אַבְרָם הָלוֹךְ וְנָסוֹעַ הַנֶּגְבָּה, מְחַקֶּה וְהוֹלֵךְ וּמְכַוֵּון כְּנֶגֶד בֵּית הַמִּקְדָּשׁ.