सिध्यतेरपारलौकिके

The substitution of आ takes for the diphthong in the causative of सिध् , when it does not refer to the next life.
The word पारलौकिक is derived from परलोक 'the next world' by adding the affix ठञ् with the force of 'for the sake of' 5.1.109. The double Vriddhi takes place by 7.3.20. The sense of the word सिध् must refer to अज्ञान or non-intelligent things for the purposes of this substitution. Thus अन्नं साधयति, ग्रामं साधयति ॥ Why do we say when not referring to the next world ? See तपस्तापसं सेधयति, स्वान्येवनं कर्माणि सेधयन्ति ॥ The force of सिध is here that of knowledge, तापसः सिद्ध्यति = ज्ञानावशेषमासादयति ॥ The ascetic acquires certain knowledge through austerities, the knowledge so acquired produces its result in the next world (परलोक) i. e. the next life, therefore, the साधन of the ascetic is for the sake of the next life, and so there is no substitution of आ for ए ॥ Why the substitution does not take place here : अन्नं साधयति, ब्राह्मणेभ्योदास्यामि 'he causes food to be prepared for the purpose of giving to the Brahmanas'. Here though the gist of the food produces effect in the next world, yet as that is the effect of दान and not of the verb सिध्, the substitution does take place. When the verb सिध् directly and not through the mediation of another action, produces paraloukika effect, then the substitution does not take place. The verb सिध् here belongs to the Divadi class and not to the Bhvadi, as the form सिध्यति in the sutra shows it.