There is invariably the substitution of ā for the diphthong of the root smi 'to smile' in the causative, when the astonishment is produced directly through the agent of the causative.,
The words णौ and हेतुभय are both understood here. The word नित्य shows that the anuvritti of विभाषा ceases. Thus मुण्डोजटिलो वा विस्मापयते ॥ Otherwise we have कुञ्चिकयैनं विस्माययति ॥ The word भय here is taken to mean स्मयति i. e. 'wondering', 'feeling astonished'. See 1.3.68 where also this meaning has been extended to भय by its connection with भीस्मि together; the proper word ought to have been हेतुस्मये in connection with स्मि, and हेतुभये in connection with भी ॥,