All employees, before entering upon their duties, shall take and subscribe the following oath to be filed and preserved by the commissioner:
“I do solemnly swear (or affirm) that I will faithfully and diligently perform all the duties required of me as_______________of the correctional system, and will observe and execute the laws, rules and regulations passed and prescribed for the government thereof so far as the same concerns or pertains to any employment, and that I will not ill-treat or abuse any offender under my care contrary to the law and the rules and regulations prescribed by legal authority. So help me God.”