A‘raj reports that once Sayyiduna Abbas bin Abdullah married his daughter to Abdur Rahman bin Hakam, and Abdur Rahman married his daughter to Abbas, and they made this exchange itself the dowry. When Sayyiduna Muawiyah (may Allah be pleased with him) came to know of this, he wrote a letter to Marwan, "because he was the caliph," and ordered that separation be made between them, and said that this is the same shighar marriage from which the Prophet (peace be upon him) had forbidden.