D&Dtools1

Effect or Area: One whip or 30-ft. line
Duration: 1 round/level or until exhausted
Saving Throw: None or Reflex partial
Spell Resistance: Yes
The air around you begins to thrash and churn with invisible forces.
This spell brings into being an invisible, whiplike tendril of force.
As an immediate action, you can command the lash to strike any creature within 10 feet of you.
The lash strikes automatically and deals 5d6 points of damage.
You must be able to see the target to be struck, but the lash otherwise ignores concealment.
As a force effect, it can even strike incorporeal or ethereal creatures.
At any point during the spell's duration, you can use a standard action to unleash a single 30-foot line of force that deals 15d6 points of damage and knocks prone any creatures in its area.
A successful Reflex save halves the damage and prevents the creature from being knocked prone.
This effect instantly ends the spell's duration.