The Religion of Abraham

We'll get into Deuteronomy at some point, but as we're reading Moses / Genesis now, it's probably worth stopping a moment to summarize the religion of Abraham, as we see it here.  Here's a non-exhaustive list of observations:

1. Abraham hears God's voice and also sees Him.  
2. Abraham's God also communicates through dreams.
3. Abraham builds altars at the places where he sees God.   The Hebrew text uses the technical term maqom to refer to these sacred sites -- the word simply means "place," but Deuteronomy specifically forbids maqoms of sacrifice other than the Jerusalem temple.
4. Abraham knows sacred trees (what is translated here as the "plains" of Mamre is really the "oaks" or "terebinths" of Mamre).  
5. Under one such sacred tree, Abraham receives three holy men as visitors, shares bread with them and washes their feet.
6. Abraham makes covenants with God.  As a result of these covenants, he receives a new name.
7. For Abraham, astronomy has a sacred dimension.  He sees the stars in a visionary context, and the stars are people (his priestly descendants).
8. Abraham has a son by a "handmaid." We already noted interesting things about royal, tented, status-conferring Sarah and his relationship with her.
9. Abraham knows the sacrifice of a son on a sacred mountain.