ā is substituted for the final of yuṣmad and asmad before the case-ending of the Nominative 1st-Case dual in the secular literature.,
As युवाम्, आवाम् ॥ Why of the nominative? Observe युवयोः, आवयोः ॥ Why in the Dual ? Observe त्वं, अहं, यूयं, वयं ॥ Why in the secular literature ? Observe
युवं वस्त्राणि पीवसा वसाथे in the Veda, so also आवम् ॥,