The power in question is Final Rebuke, a Paladin level 9 power from Divine Powers:
Daily • Divine, Reliable, Weapon
Target: One creature
Attack: Strength vs. Fortitude
Hit: 2 [W] + Strength modifier damage, and you push the target 5 squares. If the target ends this movement in a square adjacent to a solid obstacle, the target takes 1 [W] extra damage.
B is the user of the attack,
E the target, the
O is a wall, and the
Xs are empty squares.
When you use and hit with the attack:
XXXXXXOX BEXXXXXO XXXXXXXXO
… then the target ends his/her forced movement but does not hit the wall:
XXXXXXOX BXXXXXEO XXXXXXXXO
… will the target take the 1[W] extra damage or not?
And then will it work if the solid obstacle is to the left and/or right?