So they gave Jacob all the foreign gods which they had and the rings which were in their ears, and Jacob hid them under the oak which was near Shechem. Genesis 35:4 (NASB)
There is something fascinating going on here in Genesis 35. In Deuteronomy and Numbers, the text prescribes a method of dealing with idols: destroying them with fire; smashing them; tearing them down; and generally demolishing them entirely. In the case of the golden calves, it even involved grinding them down and scattering the dust of the idols into water. But here, the text says Jacob hid them. Buried them.
Some commentators point out that this event occured in Genesis, which is long before the teachings at Sinai. There were no rules on how to deal with idols, so Jacob is just kind of... winging it. Other rabbinical writings suggest that the idols had lost their potency and were no longer considered problematic, so destruction wasn't necessary. Some even hint that Jacob and company were clearly not idolaters, so it was not a temptation to them anyway; burying the idols was sufficient.
However, Torah wasn't written linearly. The writers may have had the entire story in mind as they assembled the text, so the teachings treat every part of the text as though the characters are aware of the rest of the text. That said, the writers may expect you fully understand the rules about idols, and then notice that Jacob does not adhere to those rules. He hides the idols instead of destroying them. And he hides them under the oak near Shechem. THE oak tree.
Abram passed through the land as far as the site of Shechem, to the oak of Moreh. Now the Canaanites were in the land at that time. Genesis 12:6 (NASB)
The text appears written to point us back to Genesis 12, where Abram first encounters the land of the Canaanites.