An Nawawi Hadith Number 33 : The Authority Of Ibn Abbas

The Messenger of Allah said: “Were people to be given in accordance with their claim, men would claim the fortunes and lives of [other] people, but the onus of proof is on the claimant, and the taking of an oath is incumbent upon him who denies.”

Reporters.
A fine hadith related by Al-Baihaqi and others.