Abu Hurairah narrated:
"The Messenger of Allah (ﷺ) passed judgement based on an oath along with one witness." Rabi'ah (one of the narrators) said: "A son of Ibn Sa'd bin 'Ubadah informed me saying: 'We found in a book of Sa'd that the Prophet (ﷺ) passed judgement based on an oath along with a witness.'"