9.3.2 Working with detached objects
first paragraph:
A detached instance may be reattached to a new Session (and managed by this new persistence context) by calling update() on the detached object.

should be

A detached instance may be reattached to a new Session (and managed by this new persistence context) by calling update() on the session object.


BTW: third paragraph:
Hibernate always treats the object as dirty and schedules an SQL UPDATE.,

should be

Hibernate always treats the object as dirty and schedules an SQL UPDATE,

No, you call update(object), on the object. The period problem in the third paragraph I added to the errata.

very confused.

Do you mean to call detachedObject.update(detachedObject); to reattach it?

In fact, what it calls is session.update(detachedObject); to reattach it.

You call session.update(object). The update() method works UPON the object.