Idaho Code § 34-1111

In case any person offering to vote is challenged one (1) of the judges must declare the qualifications of an elector to such person. If the person so challenged then declares himself duly qualified, and the challenge is not withdrawn, one (1) of the judges shall then tender him the elector’s oath, as prescribed by the secretary of state. No challenged elector shall have the right to vote until he has subscribed to the elector’s oath. Upon a challenged elector’s subscribing the elector’s oath, he shall be entitled to vote.