One day during the last pilgrimage which the Prophet performed when he was on a horseback with a whip in his hand a man come across him and said he had a complaint to make. The Prophet asked what the complaint was.
“Many years ago” he said “during the jahiliyyah (the pre-Islamic period) I and Tariq ibn Marqa’ had taken part in a battle. During the skirmish Tariq was badly in need of a spear and he cried: ‘Is there any person who can spare me his spear and accept remuneration for it?’ I stepped forward and asked what remuneration he would give. He said ‘I give my word that the first daughter born to me shall be brought up for you.’ I accepted the offer and handed over my spear to him. The matter was thus closed and many years elapsed. At last I recollected the pledge and discovered that a daughter had been born to Tariq and that she was of age and that he had her in his house. I went to him reminded him if the events and demanded the settlement of the debt. But Tariq went back on his pledge and broke his word of honour and wanted to start asking for mahr (dower). Now I have come to you to know whether right is with me or with him.
“What is the edge of the girl?” The Prophet inquired.
“She is grown up and white hairs have appeared in her head.”
“According to what you ask me neither you nor Tariq is in the right. Go back and look after your own affairs and leave the poor girl to look after herself.”
The man was astonished to hear this. For a moment he was absorbed in wondering what sort of a judgement it was. Was the father not in full authority regarding his daughter? If he should pay the dower to the father of the girl and if he were willingly voluntarily to hand over the girl to him was that also wrong?
The Prophet seeing him astonished and perplexed understood his state of mind and said:
“You should be sure that in the way that I have pointed out neither you nor your friend Tariq will he sinners”
source : http://www.maaref-foundation.com