Splinter of Nordrassil

The Splinter of Nordrassil is the quest reward for completing the quest, which is the epic priest quest. It is combined with the Eye of Divinity and the Eye of Shadow to form Benediction.

Source
This item is a reward from the priest quest which starts with Eris Havenfire in the Eastern Plaguelands. To see Eris, you must have the Eye of Divinity equipped. To complete the quest, you must have:
 * The Eye of Divinity
 * The Eye of Shadow