Hebrew

šām, šammā - there (HALOT 1545)

PCS
*ṯamma - there (Kogan 2015: 202)
Contrary to a widespread opinion (AHw. 1272, HALOT 1546, DUL 913), neither Akk. šumma ‘if’ nor Arb. ṯumma ‘then, afterwards’ can be related to *ṯamma