(1) An oath or affirmation in the prescribed manner shall be administered to every member of every Security Force Court and to the Law Officer or as the case may be the officer approved under section 83, before the commencement of the trial.
     (2) Every person giving evidence before a Security Force Court shall be examined after being duly sworn or affirmed in the prescribed form.
     (3) The provisions of sub-section (2) shall not apply where the witness is a child under twelve years of age and the Security Force Court is of opinion that though the witness understands the duty of speaking the truth, he does not understand the nature of an oath or affirmation.