Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: In the time of ignorance, the practice of badal (exchange) was that a person would say to another, "Let me have intercourse with your wife and I will let you have intercourse with my wife, and I will give you further benefit." So Allah the Exalted revealed this verse: «وَلَا أَنْ تَبَدَّلُوا بِهِنَّ مِنْ أَزْوَاجٍ وَلَوْ أَعْجَبَكُمْ حُسْنُهُنَّ» . Sayyiduna Uyainah bin Hisn Fazari (may Allah be pleased with him) came to the service of the Noble Prophet (peace and blessings be upon him), and at that time the Noble Prophet (peace and blessings be upon him) was present with Lady Aisha (may Allah be pleased with her). Uyainah entered without seeking permission, so the Noble Prophet (peace and blessings be upon him) said to him, "O Uyainah! Why did you not seek permission?" He replied, "O Messenger of Allah! Since I reached puberty, I have never sought permission to enter the house of any individual from the tribe of Mudar." He also said, "Who is this beautiful woman sitting beside you, O Messenger of Allah?" The Noble Prophet (peace and blessings be upon him) said, "This is Aisha, who is the mother of all the believers." He said, "Shall I not exchange her and give you a woman more beautiful than her?" The Noble Prophet (peace and blessings be upon him) said, "O Uyainah! Allah the Exalted has forbidden this act." When that person left, Lady Aisha (may Allah be pleased with her) asked, "O Messenger of Allah! Who was that?" The Noble Prophet (peace and blessings be upon him) said, "He was a foolish leader; you have seen his mental state, yet he is the chief of his people."