Dismissal

Dismissal, also known as abjure, was an abjuration spell that could send an extraplanar creature back to its plane of origin.

Effects
If the caster overcame the target's magic resistance (if any), then a momentary battle of wills ensued where the outcome was influenced by the relative difference in experience levels between the caster and the target. If the caster failed, then nothing happened, but if the caster succeeded then the creature was instantly banished from the plane of existence the creature and caster were on, back to its home plane. The caster had no control over where on the destination plane the creature would land,  and indeed the newer version of this spell sometimes sent the creature to a plane that was not its home plane.

The older version of this spell was rather harsh in that the banished creature could suffer system shock from being wrenched out of one existence and into another.

Components
The newer version of this spell required the caster's holy symbol or divine focus and also verbal and somatic components. The older version also needed holy water and some material or item that was either harmful or distasteful to the creature. If the creature had a proper name, then the caster had to speak the name as part of the verbal component.