It is narrated from Hazrat Abu Hurairah (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) forbade exchange marriages (watay satay) in which, without specifying a dowry, the exchange of relations itself is considered as the dowry. He also forbade deceptive trade and selling by throwing pebbles.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 10439