It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Noble Prophet (peace and blessings be upon him) forbade shighar marriage (exchange marriage). The narrator asked Nafi’ about the meaning of shighar, so he replied: That a man marries his daughter to someone and that person marries his daughter to him, or he marries his sister to someone and himself marries that person’s sister, and no dowry is fixed.