ša-na-mu-mu /ḏanāmum/ - to rain (VE 1403′, Kogan–Krebernik 2021b: 690)

Probably *ḏnn is the original shape of the root dissimilated in EthS and Sab, but the reverse possibility (an original *ḏnm assimilated to znn in Akkadian) cannot be excluded either (cf. DRS 336) (Kogan 2015: 442-443)