Apex Triggers throw the error SELF_REFERENCE_FROM_TRIGGER

You cannot recursively update or delete the same object from an Apex trigger.

This error often occurs when:

        * You try to update or delete an object from within its before trigger.
        * You try to delete an object from within its after trigger.   

This error occurs with both direct and indirect operations. The following is an example of an indirect operation:

       1. A request is submitted to update Object A.
       2. A before update trigger on object A creates an object B.
       3. Object A is updated.
       4. An after insert trigger on object B queries object A and updates it. This is an indirect update of object A because of the before trigger of object A, so an error is generated.