Quill of the Great Library

(Requires Attunement by a Wizard)
When you perceive a Wizard spell being cast, you
can use your reaction to activate the quill. It will
absorb the knowledge and understanding required
to copy that spell into your spellbook.
It can only retain the knowledge of one spell at a
time, and cannot be used again until the spell contained in it has been copied into a spellbook,
after which it fades. The quill automatically
generates any materials necessary to complete the process.