The affix yat comes optionally after the words denoting 'offering' and etc., in the sense of prakkritīya,
Thus आमिक्ष्यं दधि \fit for making आमिक्षा\ i. e. curd :- or आमिक्षीयं with छ ॥ So also पुरोडाश्याः or पुरोडाशीया स्तण्डुलाः, 'suitable for making Purodasa' i.e. a kind of rice. The word हवि occurs in the गवादि class 5.1.2 and it necessarily takes यत्, there being no option. The हवि here, therefore, means things denoting sacrificial offerings, and not the word-form 'havi.'
So also after अपूपादि, as, अपूप्यम् or अपूपीयं, तण्डुल्यम् or तण्डुलीयं ॥
1 अपूप, 2 तण्डुल, 3 अभ्यूष (अभ्युष), 4 अभ्योष, 5 अवोष, 6 अभ्येष, 7 पृथुक, 8 ओदन, 9 सूप, 10 पूप, 11 किण्व, 12 प्रदीप, 13 मुसल, 14 कटक, 15 कर्णवेष्टक, 16 इर्गल, 17 अर्गल, 18 अन्नविकारेभ्यश्च, 19 यूप, 20 स्थूणा, 21 दीप (पीप), 22 अश्व, 23 पत्र, 24 कट, 25 अयः स्थूण,
Vart:- The affix यत् comes optionally after words denoting modifications of food: such as सक्तु ॥ In the case of 'saktu' however, no of option is allowed. See 5.1.2.,