The Prophet ﷺ ruled that a case may be decided on the basis of an oath together with a single witness.
حدثنا محمد بن بشار حدثنا عبد الوهاب حدثنا جعفر بن محمد عن أبيه
أن النبي ﷺ قضى باليمين مع الشاهد
No references are available.
[Its isnad is sahih]. Tirmidhi narrated it in the Chapter on Rulings, the section on the oath along with [the plaintiff's testimony], hadith 1344, from Muhammad bin Bashshar with this chain.