The ቄስ has origin in Old testament not in new testament of christianity. Ethiopian Orthodox christianity and some others to some extent catholicism are influenced by Torah practice than educations of Jesus. Typical examples the Tabot and ቄስ and many other jewish practices. Ethiopia and Eritrea have been heavily influenced by Jewish culture and traditions but failed to become strong in the new testament commandments, experience spiritual revival although they accepted the truth!
Colonialist isolation and islam destructive wars contributed to the unique way Ethio-Eritrean churches thrived!