Praudhamanorama p24

p24

'cādayo'sattve' (P. 1.4.57). Why [say] 'not meaning a substance (adravyārthāḥ)'? [Consider] 'paśuḥ' (an animal). A substance is endowed with gender and number. But here it certainly applies: 'lodhaṃ nayanti paśu manyamānāḥ'—where 'paśu' is in the sense of 'properly'.
'prādayaḥ' / 'upasargāḥ kriyāyoge' (P. 1.4.58–59). 'nis' and 'dur' end in 's', because of the mention 'nisastapatau' (P. 8.3.102), and because the Bhāṣyakāra said, in the section 'ayogavāhānāmaviśeṣeṇa' (of the unjoined sounds without distinction), citing 'niṣkṛtam' and 'duṣkṛtam', 'the visarjanīya which is of the letter "s" preceded by i or u'. Vāmana also says the same on the rule 'upasargasyāyatau' (P. 8.2.19). Haradatta, on that very rule, says they also end in 'r', because of the mentions 'niraḥ kuṣaḥ' (P. 7.2.46) and 'suduroradhikaraṇe' (P. 3.2.180).