RCW 5.28.050Form of affirmation.Any person who has conscientious scruples against taking an oath, may make his or her solemn affirmation, by assenting, when addressed, in the following manner: 'You do solemnly affirm that,' etc., as in RCW 5.28.020.[ 2011 c 336 s 135; 2 H. C. s 1697; 1869 p 379 s 5; RRS s 1268.]
Washington Legal Code