Mahr(dower) is a sum of money or something in kind which a husband is required to pay to his wife at the time of marriage or make a commitment that it shall be paid later. It is erroneously believed by some that mahr (dower) is the price of owning a wife.
In reality, the payment of mahrhas a deep symbolic significance: Islam has entrusted the husband with the responsibility of supporting his wife and children. It is he who must earn to fulfil the requirements of the family. The mahrmoney is only a token of this responsibility. In other words, when a man pays this sum, he makes a symbolic expression of the fact that he has taken the financial responsibility of the woman he intends taking as his wife. Consequently, it is in the spirit of this commitment that he pay the agreed sum before he takes home the bride.
It would not be out of place to mention that the amount of the mahrmoney, as the Qur’ānasserts, should be fixed keeping in view the social customs and traditions of a society :
وَآتُوهُنَّ أُجُورَهُنَّ بِالْمَعْرُوفِ(25:4)
... and pay them their dowers according to the custom. (4:25)
Also, as mentioned above, it is in the fitness of things that the amount be paid to the wife as soon as possible since it symbolizes one of the primary responsibilities of the husband.