Karnatakabhashabhushana 4.3.2

4.3.2

yat kriyate tat karma ucyatē. tad ēkaṁ nirvaryaṁ vikāryaṁ prāpyaṁ vaiṣayikam iti caturthā bhidyatē. asminn arthē dvitīyāvibhaktir bhavati.

That which is effected is called the object. It is classified into four kinds, namely: to be produced, to be modified, to be attained, and contextual. In this sense, the accusative case inflection occurs.