Abraham is possibly referring here to his and ABIMELEK's gods.
I find it hard to accept Abraham mentioning his God and the others in
one breath
( as distinct from his combining YHWH and )L (LYON ).
I would find it easier to believe that he refered ONLY to Abimelech's
gods,
i.e. speaks in a language that Abimelech would best understand.
However, Abraham states that God MADE him wander, obviously that must
have been for some purpose.
It wouldn't make sense for Abimelech's gods to send him for that purpose
(whether the purpose is reaching Canaan, or spreading God's word).
The YIR)-AT ELOHIM of verse 11 refers to the mores of the local
population.
Or some supernatural fear that God would send, as in
WYHY XTT ELOHIM ...
It would be greatly interesting to know of other such instances in which
what Elohim
did is being said in the plural.
I can't think of any others. Of course there are other names of God in
the plural.