Reputed viewpoint among succeeding and contemporary jurisprudents regarding to the claim about the dead is that in addition to evidence, the claimant must take an oath. This oath documented in several narrations of Ahl-Bayt (pbut) is called “yamin estedhari” or “motammem estedhari” (supplementary oath). This essay has evaluated proving narrations of “Yamin Estedhari” and the result is chains of transmission of these narrations are faulty or their content don’t prove this oath, instead the content concerns other contexts regarding to either inversion of claim or single just witness besides oath of claimant. Therefore, considering mostaf?? general narration and some of special reasons, claimant has a single obligation of giving evidence.