1)
Why does the Torah see fit to inform us that Avraham went home?
1.
Rashi: Once the Judge (Hashem) left the scene 1 , it was time for the defense counsel to follow suit.
2.
Seforno: The Torah is telling us that, unlike Kayin who left Hashem's presence, 2 Avraham waited in prophecy-mode) until Hashem had departed, before he left.
1
Moshav Zekenim: Really, one cannot say that Hashem "left". It is a mere anthropomorphism.
2
See Bereishis, 4:16.
