अभूततद्भावे कृ-भ्व्-अस्तियोगे सम्पद्यकर्तरि च्विः

The words अभुततद्भावे are not words of Panini, but of the Vartika-Kara, and read into the sutra by the author of Kasika. When something or somebody has become that which is expressed by the stem, then this affix च्वि is added. When the cause of a thing arrives at the state of being that very thing so produced, it is said to be abhutatadbhava 'the state of that what it was not'. The agent of the action of attaining is called sampadya karta. Thus अशुक्लः शुक्लः सम्पद्यते, तं करोति = शुक्लो करोति \he whitens\ -- when some one who is not white becomes white i. e. some one makes him so, then we say शुक्ली करोति ॥ So also शुक्ला भवति, शुक्ली स्यात् = मलिनं शुक्ली भवति ॥ The word शुक्ली is thus formed:- शुक्ल + च्वि = शुक्ल् + ई + (the अ of sukla is changed into ई by 7.4.32, and the whole affix is elided by 6.1.67) = शुक्ली ॥ Similarly घटी करोति मृदम् 'he makes a jar of the clay': घटी भवति, घटी स्यात् ॥

Why do we say 'becoming that what it was not'? Observe शुक्लं करोति 'he makes white'. Here the thing that has been made white is not expressed, and hence no affixing takes place.

Why do we say \when conjoined with the verbs कृ, भू and अस्?\ Observe अशुक्लः शुक्लो जायते. The verb here is जन् 'to produce', and hence no affixing. Why have we used the words sampadya kartari 'the agent that has attained', for even without their use, the words abhuta-tadbhava 'becoming what the thing previously was not', would imply that the attainment was of the agent? The use of sampadya-kartari shows that the attainment spoken of here should be of the 'agent', and not of any other karaka, as, अदेवगृहे देवगृहे भवति 'becoming in the temple what was not before in the temple; such as a tree &c'. Here the karaka is locative and not agent, and the becoming of what the thing previously was not refers to location and not to agency. Hence no affix is added here.,