Mehri

sɛ̄ - nine (ML 338)

Throughout MSA, *t- in the reflexes of PS *tišˁ- ‘nine’ is lost, whereas *š is reflected as *s (see Testen 1998a and SED I p. xci. for the affricate theory of PS consonantism).

PS
*tišˁ- - nine (Kogan 2009: 73)