Abu Malik al-Ashja'i (may Allah have mercy on him) said: I came to Qadi Shurayh (may Allah have mercy on him) when two men came with a dispute over a riding animal, (one claiming) that the animal had given birth in his care. Qadi Shurayh (may Allah have mercy on him) asked for witnesses. He brought a group of eight people as witnesses. The one in whose possession the animal was said: Ask him to swear an oath. So the judge asked him to swear an oath. He said: Look, I have presented eight witnesses! Qadi Shurayh (may Allah have mercy on him) said: Present as many witnesses as you like; as long as you do not swear the oath yourself, judgement will not be given in your favour.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الدعوى والبينات / 21250