Sayyiduna Jabir bin Abdullah (may Allah be pleased with them both) says that the Messenger of Allah (peace and blessings be upon him) said: "Women should be married only to an equal (kuf'), only their guardians should give them in marriage, and there should be no dowry less than ten dirhams."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصداق / 14383