In a bahuvrīhi samāsa , after the words idam , etad and tad the last syllable of prathama and of a proper ordinal numeral as the acute accent (udātta) when the number of times of an action is meant.,
Thus इदं प्रथमं गमनं भोजनं वा = स इदमप्रथमः꣡ 'this is the first time of going or eating'. इदं द्वितीयः꣡, इदं तृतीयः꣡, एतत्प्रथमः꣡, एतद्द्वितीयः꣡, एतत्तृतीयः꣡ तत्प्रथमः꣡, तद्द्वितीयः꣡ तत् तृतीयः꣡ ॥ Why do we say 'in a Bahuvrihi?' Observe अनेन प्रथमः = इदंप्रथमः ॥ Here the first member being in the third case retains its accent by 6.2.2. Why do we say \after idam &c\. Observe यत्प्रथमः = यःप्रथमं एषाम्, here the first term retains its accent by 6.2.1. Why do we say 'of prathama and the Ordinals'? Observe तानि बहून्यस्य = तद्बहुः ॥ Why do we say 'in counting an action'? Observe अयं प्रथम एषां = त इद प्रथमाः ॥ Here substances are counted and not action. Why do we say 'in counting'? Observe अयं प्रथम एषां = इदं प्रथमाः i.e. इदं प्रधानाः ॥ and the word प्रथम means here 'foremost', and is not a numeral. When the कप् affix is added, the acute falls on the last syllable preceding कप् ॥ As इदं प्रथमकाः ॥ The Bahuvrihi governs the subsequent sutras upto 6.2.178.,