Noun
a rule that declares not admissible as evidence any statement other than that by a witness
Source: WordNetCertain exceptions to the hearsay rule have been permitted; for instance, admissions by the defendant are admissible, as are dying declarations. Source: Internet
If the affiant is a party in the case, the affiant's opponent may be successful in having the affidavit admitted as evidence, as statements by a party-opponent are admissible through an exception to the hearsay rule. Source: Internet