The la denoting the agent, when the action affecting the agent is similar to the action which affects the object, is treated as if it were a la denoting the object.,
This rule applies to reflexive verbs. \This direction implies the substitution for the operations incident to a tense-affix or ल, denoting an agent, of all the operations, which fall to be performed when the tense-affix or ल denotes the object. Hence there shall be the affixing of यक् (III. I.67) the employment of Atmanepada terminations (I. 3. I3), the substitution of चिण् for च्लि (III. I. 66), and the treatment of the word as directed in sutra 6.4.62.\ (Dr. Ballantyne). Thus भिद्यते काष्ठं स्वयमेव 'the wood splits of itself'; अभेदि काष्ठं स्वयमेव 'the wood splits of itself'.
When an action is participated by or affects the agent in the same way as is done by the object, the agent is treated like an object.
When in an object, though it stands as an agent, the action is perceived to take place as in an object, then that agent becomes like an object; and all grammatical rules applicable to the object apply to such an agent.
The word वत् 'like' in the sutra signifies that the rules which apply to an agent also come into operation; thus भिद्यते कुसूलेन.
The word कर्मणा 'with the object' in the sutra indicates that the tulyakriya or similarity of action must be with the object, and not with the instrument or the location. Thus साध्वसिश्छिनत्ति 'the sword cuts well'; here 'sword' is not agent but instrument. So also साधु स्थाली पचति 'the pot cooks well'; here स्थाली is a location.
This 'karma-vad-bhava, the passive-like-construction takes place only in cases of some verbs'.,