If I cast Retreat on my unit at Dream Tree, do I draw a card from the tree before the unit returns to hand?

Ruling: Yes, you will draw a card from Dream Tree before the unit returns to hand.

Sequence:

• Cast Retreat targeting a friendly unit at Dream Tree (spell goes on the chain)
• Dream Tree sees you targeting a local friendly unit and triggers
• Dream Tree's trigger is added to the chain
• Dream Tree's trigger resolves first (draw a card)
• Retreat resolves (unit returns to hand)

Nuances:

• Dream Tree triggers off targeting a friendly unit at itself, not off the spell resolving