The protective aura around this spellbook prevents anyone from opening it. This magical lock can be suppressed by using the Knock spell. Closing the book again reactivates the lock. You ignore the magical lock if you are attuned to this book. 

While attuned to this spellbook, you can cast the Blade Ward cantrip. Once per day, when you prepare abjuration spells using this book, you gain a gift of preservance. This allows you to use your reaction when you are hit by an attack to reduce the damage taken by 1d6. 

If this spellbook is found or bought, it may contain abjuration wizard spells. Here is an example of the spells that may be found within : 

1st level :  Mage Armor, Shield, Protection from Evil and Good

2nd level : Arcane Lock

3rd level : Counterspell, Dispel Magic, Glyph of Warding

4th level : Banishement, Stoneskin

5th level : Planar Binding

Notes: abjuration wizard