"Narrated a man from the Companions of the Prophet: Muhammad ibn Abdur-Rahman ibn Thawban reported on the authority of a man from the Companions of the Prophet (peace be upon him): When Ali married Fatimah, daughter of the Apostle of Allah, he intended to have intercourse with her. The Apostle of Allah prohibited him to do so until he gave her something. Ali said: "I have nothing with me, Apostle of Allah." The Prophet said: "Give her your coat of mail." So he gave her his coat of mail, and then cohabited with her."

"Dictionary of Islam, 6, p91

Dower is considered by some lawyers to be an effect of the marriage contract, imposed on the husband by the law as a mark of respect for the subject of the contract - the wife; while others consider wife, and its payment is necessary for the usufruct of the wife, and its payment is necessary, as upon the permanency of the matrimonial connection."