Ibn ‘Abbas reported the Prophet (ﷺ) as saying, “If people were given what they asked when they brought a case some would claim the lives and property of others; but the oath must be taken by the defendant.” Muslim transmitted it. In the commentary on his work by Nawawi it says that in Baihaqi’s version with an isnad which is hasan or sahih there is an addition on the authority of Ibn ‘Abbas which is traced to the Prophet, “But the proof lies on the plaintiff and the oath must be taken by him who rejects the claim.”