तस्मादित्युत्तरस्य

An operation caused by the exhibition of a term in the Ablative 5th case, is to be understood to enjoin the substitution of something in the room of that which immediately follows the word denoted by the term.
This sutra explains the force of words in the ablative case when employed in these aphorisms. As the locative case refers to a preceding word, so the ablative refers to a succeeding word.

Thus sutra 8.4.61 declares that 'after उद्, of stha and stambha, the substitute is a letter belonging to the class of the prior.' Thus उद् + स्थानम्. Here the word उदः is exhibited in the original sutra in the ablative case, and by the present sutra it means that a dental letter थ् must be substituted in the place of sthana, and by 1.1.54 ante, this dental takes the place of स्; we have उद् + थ्थानम् = उत्थ्-थानम्. Similarly in sutra तिङ् ङतिङः8.2.18, 'a word ending in a conjugational affix, when following after a word ending in a non-conjugational affix, becomes anudatta.') Here the word 'atinah' is exhibited in the ablative case, therefore, the operation directed by this aphorism, namely, the substitution of anudatta accent, must take place in the word that follows. Thus ओदनं पचति; but not so in पचत्योदनमिति ॥