Proto-Semitic *ṣ̂yḳ> Akkadian siāḳu "to be narrow"
Such dissimilation is more likely if the emphatics were glottalized.
It also affected loanwords, such as Amorite *qṭl > Akkadian ḳtl. In rare cases it did not apply, such as ḳaṣû instead of kaṣû.[3]
If Proto-Semitic emphatics were ejectives, then the Geers's law is explained as a manifestation of the widespread constraint in languages having ejectives, which forbids cooccurrence of two ejectives in a root.[4]
Geers, Frederick W. (1945), "The treatment of emphatics in Akkadian", Journal of Near Eastern Studies, 4 (2): 65–67, doi:10.1086/370740, S2CID161071735.
Kogan, Leonid (2011), "Proto-Semitic Phonetics and Phonology", in Weninger, Stefan (ed.), The Semitic Languages:An International Handbook, Walter de Gruyter, pp. 54–151
Streck, Michael P (2011), "Babylonian and Assyrian", in Weninger, Stefan (ed.), The Semitic Languages:An International Handbook, Walter de Gruyter, pp. 359–396
Bomhard, Allan R.; Kerns, John C. (1994), The Nostratic Macrofamily: A Study in Distant Linguistic Relationship, Walter de Gruyter