समर्थानां प्रथमाद् वा

All the three words, viz. (1) समर्थानां 'of the words in construction' (2) प्रथमात् 'after the first'; (3) वा 'on the alternative', exert a governing influence on the subsequent aphorisms, up to the aphorisms which leave to the words their own denotation : that is to say, up to the end of the second chapter of the fifth Book; before the beginning of the sutra प्राग्दिशो विभक्तिः 5.3.1. The present sutra as a whole, of course, has no applicability to the affixes which leave to the words their own denotation (स्वार्थिक); for the latter affixes are in many cases compulsory and not optional, as are the affixes to be taught hereafter in Book Fourth and the first and second chapters of Book Fifth.

These affixes will come after the word, that is signified by the first of the words in construction, in an aphorism. Thus 4.1.92 declares तस्यापत्यम् 'his son'. Here the first word is तस्य 'his', therefore, the affixes forming the patronymics will come after the word signified by 'his': i.e. after the word in the genitive case. As उपगोरपत्यं = ओपगवः 'the son of Upagu'. Here the affix अण् comes after the word उपगु which is the first word representing 'tasya' in the genitive case in the sentence उपगोरपत्यम् ॥ Similarly in the sutra तेनरक्त रागात् 4.2.1; here the first word is तेन, therefore, the affix will be added to the word in the instrumental case in a sentence representing the word तेन 'by which'; as कषायेण रक्तं वस्त्रं = काषायं, 'Kashaya is a cloth, coloured by Kashaya'. Similarly in sutra तत्र भवः 'there staying' (IV. 3. 53.) here the first word is तत्र, 'there', in the locative case, therefore the affix will be optionally added to the word in the locative case in a sentence, representing the word तत्र 'there' : as स्रुघ्ने भवः = स्रौघ्नः \who stays in Srughna'.

The word समर्थानाम् is the genitive plural of समर्थ, and the force of the genitive is that of specification or 'nirdharana':- i. e. 'among the words in construction, the first is specifically pointed out as the prakriti or base, to which the affix is to be added'. Why do we say \among the words in construction\? Witness कम्बल उपगोरपत्यं देवदत्तस्य 'the blanket of Upagu; the son of Devadatta'. Here the two words उपगोरपत्यं are not in construction, for उपगोः governs कम्बलः, and अपत्यं is governed by देवदत्तस्य ॥ Why do we say \after the first\? So that the affix may come after the first word उपगोः in the genitive case, and not after अपत्यं which is in the nominative case, Why do we say \in the alternative\ ? Because the same idea may also be expressed by a sentence; thus we may say उपगोरपत्यं, instead of the Taddhita formed word औपगवः ॥ The same idea may also be expressed by a compound word (samasa); as उपग्वपत्यम् 'the son of Upagu'. In fact, the samasa rule here is not superseded by Taddhita-rule, as it otherwise would have been by (1. 4. 2.) because the anuvritti of अन्यतरस्याम् is understood here: so that in the alternative when the Taddhita affix is not employed, the samasa rules will find scope.

This sutra has been thus rendered by Dr. Bohtlingk: \when hence forth the meaning is specified in which an affix is to be added, then one should know that the rule applies to the first of those words which are associated with one another in sense, and that the affix is optional\.,