In the room of etad in the case of re-employment there is the substitution of the gravely accented aś when the affixes tra -- saptamyāstral [[5.3.10]] and tas -- pañcamyāstasil [[5.3.7]] follow, and the affixes tra and tad are anudātta (gravely accented) also.,
Thus अत्र 'here,' and अतस् 'hence' in the following :- एतस्मिन् ग्रामे सुखं वसामः ; अथो अत्र युक्ता अधीमहे । 'We live in this (etasmin) village, happily, therefore let us read with full devotion in this (atra).' एतस्माच्छात्राच्छन्दोऽधीष्व, अथो अतो व्याकरणमप्यधीष्व । 'Learn from this student Prosody and also learn from him Grammar.' By rule (V. 3. 5.) अश् is declared to be the substitute of एतद्; its repetition here is to indicate that this अश् of anvadesa is anudatta.,