207. Before the lingual and dental sibilants

Before the lingual and dental sibilants, ṣ and s, final n remains unchanged; but a t may also be inserted between the nasal and the sibilant: thus, tā́n ṣáṭ or tā́nt ṣáṭ; mahā́n sán or mahā́nt sán.

a. According to most of the grammarians of the Prātiçākhyas (not RPr.), the insertion of the t in such cases is a necessary one. In the manuscripts it is very frequently made, but not uniformly. It is probably a purely phonetic phenomenon, a transitional-sound to ease the double change of a sonant to a surd and a nasal to a non-nasal utterance—although the not infrequent cases in which final n stands for original nt (as in bharan, abharan, agnimān) may have aided to establish it as a rule. Its analogy with the conversion of n ç to ñch (203) is palpable.