Hafs bin Maymun (may Allah have mercy on him) said: I took a dispute to al-Sha'bi (may Allah have mercy on him) concerning a wound that exposes the bone (mudihah). The assessor testified that it was a wound exposing the bone, so the one who had inflicted the wound said to al-Sha'bi (may Allah have mercy on him): Will you accept the testimony of a single man (against me)? Al-Sha'bi (may Allah have mercy on him) said: The assessor has testified that this wound exposes the bone, and the wounded man will swear to the same. The narrator said: So al-Sha'bi (may Allah have mercy on him) gave judgement in it.
Hushaym narrates from Mughirah (may Allah have mercy on him) that al-Sha'bi (may Allah have mercy on him) said: The people of Madinah judge by an oath and a witness.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 20682