In the parasmaipada s-Aorist there is vṛddhi of the a of vada , vraj and of any vowel, without distinction, of the aṅga (stems) ending in a consonant.,
As अवादीत्, अव्राजीत् ॥ This debars the option in the case of these two roots, which would have otherwise obtained by 7.2.7. So also of stems ending in consonants: as अपाक्षीत्, अभैत्सीत्, अच्छैत्सीत्, अरौत्सीत् ॥ By the splitting up of the sutra (yoga-vibhaga) these forms could be evolved without using the word हलन्त in the sutra. Thus (1) वदिव्रज्योः \In the room of the अ of वद and व्रज् there is Vriddhi\, (2) अचः \In the room of the vowel of the stem there is Vriddhi\. The word \stem\ is understood throughout these chapters. If the vowel be at the end of the stem, there would be Vriddhi by (VII. 2. I), and if in the middle of the stem, then the verb ends with a consonant, and still there will be Vriddhi by our rule. The use of the word हलन्त in the sutra indicates that the rule applies when more than one consonant even is at the end : as अराङ्क्षीत्, अभाङ्क्षीत् ॥
Had the word हलन्तस्य not been used in the sutra, then the following maxim would have applied \येन नाव्यवधानं तेन व्यवहितेऽपि वचनप्रामाण्यात्\ ॥ The rule would have applied where only one consonant intervened between the vowel and the affix, but not when more than one consonant intervened. But it is intended that the rule should apply to such cases also.
The form उदवोढाम् is thus evolved. To the root वह् we add सिच् in the second Person singular. Thus वह् + स्ताम् ॥ Now there appears the Vriddhi rule on the one side; and the rule requiring the change of ह to ढ 8.2.31 the rule requiring the elision of स् 8.2.26, the rule requiring the change of त into ध 8.2.40, then the rule requiring the change of घ into ढ, and then the elision of one ढ 8.3.13 on the other. What rule is to be applied first-the Vriddhi or the other rules? The Vriddhi rule is to be applied first, because the other rules are considered as asiddha 8.2.1: and after that we apply the other rules : and afterwards on account of the elision of ढ, we change the Vriddhi आ into ओ 6.3.112. The equation will be something like this:- वह् + स्ताम् = वाह् + स्ताम् 7.2.3 = वाढ् + स्ताम् 8.2.31 = वाढ् + ताम् 8.2.26 = वाढ् + धाम् 8.2.80 = वाह् + ढाम् 8.4.41 = वा + ढाम् 8.3.13 = वोढाम् 6.3.112. This with the upasarga उत् and the augment अ becomes उदवोढाम् ॥ Similar is the evolution of उदवोढम् with स्तम् ॥ Once the अ has been Vriddhied into आ, there is no Vriddhi of ओ ॥ Had we not first Vriddhied the वह् into वाह्, but applied the vriddhi rule last, then there would have been vriddhi of ओ, as वौढाम् which is wrong. In fact where there has not taken place vriddhi first, there ओ is vriddhied, as = सोढामित्रस्यापत्यं = सौढामित्रिः ॥,