en_tn/psa/098/001.md

his right hand and his holy arm

These phrases mean basically the same thing and are used together for emphasis. Also, his "hand" and "arm" are used to refer to his power and strength. AT: "his mighty power and great strength," (See: rc://en/ta/man/translate/figs-metonymy and rc://en/ta/man/translate/figs-doublet)