It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that the Prophet (peace and blessings be upon him) said: "It is not correct for the collector of zakat to stay at a distance and call the zakat payers, nor is it correct for the zakat payers to bring the collector of zakat forward or backward from his appointed place. And there is no validity in Islam for exchange marriages (watay satay ke nikah)."