From OB on. Fem. summatu (Var. simmatu, šummatu, šimmatu) — from OAkk. on. The fem. form is by far more widely attested from OB on (in OAkk. as a personal name only). The masc. form is less common, attested mostly in literary texts (e.g. UET 6 396.25 idammumam kīma su-mi-[i]m ‘he moans like a dove’, OB). Both forms are discussed in Salonen 1973 254-8.