Marriage to an Ex-husband’s Uncle
Islam does not prescribe something unless there is a kind of harm included in it, nor does it prohibit something that has a benefit for people. Allah declared in the Qur’an that the mission of the Prophet (peace be upon him) is to make lawful good things and disallow bad things. In addition, in Islamic Sharia kinship and family relations are accurately and decisively determined, because of things that are based up on them of matters of relationships, children, matters of inheritance, etc.
Regarding this question, Da`iyah, Zienab Mostafa, a prominent Muslim Scholar and Da`iyah, stated,
“The Qur’an says:
“Forbidden unto you are your mothers, and your daughters, and your sisters, and your father’s sisters, and your mother’s sisters, and your brother’s daughters and your sister’s daughters, and your foster-mothers, and your foster-sisters, and your mothers-in-law, and your step-daughters who are under your protection (born) of your women unto whom ye have gone in – but if ye have not gone in unto them, then it is no sin for you (to marry their daughters) – and the wives of your sons who (spring) from your own loins. And (it is forbidden unto you) that ye should have two sisters together, except what hath already happened (of that nature) in the past. Lo! Allah is ever Forgiving, Merciful.” (An-Nisa’: 23)
Based on this verse, as long as a person’s ex-husband is not a relative to the man she wants to marry as a father, brother or son by way of fosterage (rada`ah), then the marriage is permissible and there is no restriction. Being just an uncle is not a predicament for marriage.
Furthermore, it should be noted that this could only be done after all divorce consequences have come to an end.
On the other hand, it is worth mentioning that marriage in Islam is not a ritualistic act. Rather, it is a civil ceremony as well as declaration of marriage happens on the community scale; the agreement of both parties is confirmed and the marriage legislator is just an appointed person by the state to officiate the marriage. So, it is also civil in away.”
May Allah grant all success