The Prophet is closer to believers than their soul, and his wives are their mothers, blood relatives have more claim in one another than the believers and the migrants according to the Book of Allah, whatever you are doing any goodness to your closest friends in a known manner is exempted from this, that is the decree underlined in the Book.
The believers have to give preference to the Prophet rather than his soul. The wives of the Prophet are like believers’ mothers so believers are not allowed to marry them. According to the Lord’s Book, inheritance is limited to blood relatives only. But to the believers and the migrants who came to them, it is not prohibited to give help from the wealthy considering the dos and Don’ts of the Lord’s Book. The bequest is limited to one-third of the total wealth. See explanation 2: 180-182; 4: 7-10, 80.