Rashi on Genesis 12:8/רש"י על בראשית י״ב:ח׳

1ויעתק משם AND HE REMOVED FROM THERE — supply the word אהלו “his tent”.

2מקדם לבית אל means ON THE EAST OF BETHEL. Consequently Bethel lay to his west, and that is what it states בית אל מים BETHEL ON THE WEST.

3אהלה HIS TENT — This word is written with a ה suffixed instead of the usual ו so that it may read אָהֳלָהּ “her tent” to intimate that first he pitched a tent for his wife and afterwards one for himself (Genesis Rabbah 39:15).

4ויבן שם מזבח AND HE BUILDED THERE AN ALTAR — He perceived by the gift of prophecy that his descendants would once stumble (fall into sin) there through Achan’s transgression (see, Joshua 7): therefore he prayed there for them (Genesis Rabbah 39:15).