Charles Ellicott Commentary Genesis 35:4

"And they gave unto Jacob all the foreign gods which were in their hand, and the rings which were in their ears; and Jacob hid them under the oak which was by Shechem." — Genesis 35:4 (ASV)

Earrings. —Earrings seem to have been worn not so much for ornament as for superstitious purposes, being regarded as talismans or amulets. Hence it was from their earrings that Aaron made the golden calf (Exodus 32:2–4).

The oak. —Not Abraham’s oak-grove (Genesis 12:6), referred to probably in Judges 9:6; Judges 9:37 —the Hebrew word in these three places being êlôn —but that under which Joshua set up his pillar of witness (Joshua 24:26), the tree being in both these places called allâh, or êlâh, a terebinth.