It is narrated from Sayyiduna Abu Waqid al-Laythi (may Allah be pleased with him): We were with Sayyiduna Umar (may Allah be pleased with him) at al-Jabiyah when a man came and said: My wife has committed adultery with my slave, and she also confesses it. So Sayyiduna Umar (may Allah be pleased with him) sent me, as one of a group of ten men, to his wife, to go and ask her. We went, and his wife was a very young girl. We said to her: Your husband says this, and we have come to ask you; what do you say? She said: He is telling the truth. So on the order of Sayyiduna Umar (may Allah be pleased with him), we stoned her with stones. [Sahih]
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحدود / 16934