Oregon constitution
Article IV: legislative branch
Section 31

The members of the Legislative Assembly shall before they enter on the duties of their respective offices, take and subscribe the following oath or affirmation;–I do solemnly swear (or affirm as the case may be) that I will support the Constitution of the United States, and the Constitution of the State of Oregon, and that I will faithfully discharge the duties of Senator (or Representative as the case may be) according to the best of my Ability, And such oath may be administered by the Govenor [sic], Secretary of State, or a judge of the Supreme Court.