Abd al-Rahman (the father of al-Qasim) narrated: A man was brought to Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) who had been found with a woman under a single quilt. He gave each of them forty lashes and made them both stand before the people. The woman's family and the man's family went to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) and complained to him. Sayyiduna Umar (may Allah be pleased with him) asked Sayyiduna Ibn Mas'ud (may Allah be pleased with him): "What are these people saying?" He said: "I did that." Sayyiduna Umar (may Allah be pleased with him) asked: "Did you see it yourself?" He said: "Yes." The narrator said: So they began saying: "We came to him to get our right, and here he (Umar) is asking him himself!"
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 9659