Even as harm befalls you, you draw on the earth for the strength to shrug it off.

Encounter   ✦     Primal
Immediate Reaction      Personal

Trigger: You are subjected to an effect that a save can end

Effect: You make a saving throw against the triggering effect, with a power bonus to the saving throw equal to your Strength modifier.

Published in Player's Handbook 2, page(s) 161.