When a term is exhibited in the seventh case in these sūtras, the operation directed, is to be understood as effecting the state of what immediately precedes the which the term denotes.,
This is a declaratory or interpreting sutra. When in a sutra, a word is used in the locative case, the operation ordained by that sutra is to be performed on the word preceding it. Thus in the sutra इको यणचि 6.1.77 the word अचि is in the locative case, which sutra, therefore, means that इ, उ, ऋ लृ followed by a vowel (अच्) are changed into य्, व्, र्, ल्, (यण्). The literal translation of the sutra being:- 'Of इक् there is यण् in अच्.' The force of 'in' or the locative case being to induce changes in the letter preceding the vowel. Thus दधि + उदकम् = दध्युदकम्; So मध्विदम्, पचत्योदनम् ॥
The word nirdishta (meaning 'exhibited') has been used in the sutra to indicate immediateness. Thus in अग्निचित्, the इ of अग्नि the is not directly followed by the इ of चित्, there being the letter च् intervening, therefore, rule 6.1.77, does not apply here : and we have no sandhi.,