Sa'id bin Amr bin Shurahbil bin Sa'id bin Sa'd bin Ubadah narrates from his father, from his grandfather, that the Messenger of Allah (peace and blessings be upon him) gave judgement on the basis of an oath together with a single witness in matters of rights.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 5342