अपस्पृधेथाम्-आनृचुर्-आनृहुश्-चिच्युषेतित्याज-श्राताः श्रितम्-आशीराशीर्ताः

The word छन्दसि is understood here. From the root स्पर्द्ध 'to challenge', is formed अपस्पृधेथाम् being the Imperfect (लङ्), 2nd Person Dual, Atmanepada : there is reduplication of the root, vocalisation of र्, and the elision of अ irregularly. As, इन्द्रश्च विष्णो यदपस्पृधेथाम् ॥ In secular language the form is अस्पर्धेथाम् ॥ Some say, it is derived from स्पर्द्ध with the preposition अप, the vocalisation of र, the elision of अ, and the non-prefixing of the augment अट् in the Imperfect 6.4.75. The counter-example of this will be अपास्पर्द्धेथाम् ॥ From अर्च and अर्ह 'to respect, to worship', are derived आनृचुः and आनृहुः in the Perfect before the 3rd person plural उस्, there being vocalisation of र and the elision of अ irregularly. Then there is reduplication, then ॠ changed to अ, then the lengthening of this अ, then the addition of the augment म, as : अर्च् + उस् = ॠच् + उस् = ॠ + ॠच् + उस् + अ + ॠच् + उस् 7.4.66 = आ + ॠच् + उस् 7.4.70 = आ + न् + ॠच् + उस् 7.4.71 = आनृचुः ॥ The irregularity consists in the samprasarana with the elision of अ ॥ Thus यवग्रा अर्कमानृचुः, न वसून्यानृहुः ॥ The secular forms will be अनर्चुः, आनर्हुः ॥ The form चिच्युषे is the Perfect 2nd person singular of the root च्युङ् 'to go': there is vocalisation of the reduplicate, and the non-addition of the augment इट् before the affix से ॥ This is the irregularity. The regular form is चुच्युविषे ॥ The form तित्याज is the Perfect of त्यज्, the vocalisation of the reduplicate is the irregularity. The regular form is तत्याज ॥ From the root श्रीञ् 'to cook', is derived श्राता before the Nishtha affix, श्री changed to श्रा irregularly. As श्रातास्त इन्द्रसोमाः ॥ The form श्रितं is also derived from the same root by shortening the vowel with the same affix. As सोमो गौरी अधिश्रितः, श्रिता नो गृहाः ॥ Some say the श्रा substitution of श्री takes place when the word refers to सोम, in the plural, and श्रि when it refers to other than सोम ॥ Sometimes the word श्रातः is seen in the singular, referring to objects other than सोम । Thus यदि श्रातो जुहोतन ॥ In fact, the exhibition of the word श्राताः in the plural in the sutra is not absolutely necessary. The words आशीर् and आशीर्त्तः are from the same root श्री, with the prefix आङ् and taking the affixes क्विप् and क्त respectively. Before these श्री is replaced by शीर्, and the non-addition of न in the Nishtha is irregular. As, तामाशीरा दुहन्ति आशीर्त्त ऊर्ज्जम्, क्षीरैर्मध्यत आशीर्त्तः ॥,