Moritte of the Frost in hand or in the command zone.
Staff of Eden and Marit Lage's Slumber on the battlefield.
({2} magic symbol) ({G} magic symbol) ({U} magic symbol) ({U} magic symbol) plus enough mana to pay for commander tax, if applicable available.
Steps
Cast Moritte of the Frost from your hand or from the command zone by paying ({2} magic symbol) ({G} magic symbol) ({U} magic symbol) ({U} magic symbol) plus commander tax, if applicable, choosing to have it enter the battlefield as a copy of Staff of Eden.
Put Moritte of the Frost into your graveyard due to the legend rule.
Morrite of the Frost's enters-the-battlefield ability and Marit Lage's Slumber's first ability trigger.
Resolve the Marit Lage Slumber trigger, causing you to scry 1.
Resolve the Moritte of the Frost trigger, returning Moritte of the Frost from your graveyard to the battlefield as a copy of Staff of Eden.