Praise be to Allaah.
The Muslims should put an end to all disputes among
themselves that may generate resentment and hatred. The believers are
brothers and Allah has enjoined reconciliation between believers who are
fighting. He also described them as brothers in the faith.
So they should try to forget this resentment, especially if
they have any measure of religious commitment, as it says in the question.
If the guardian hopes that this marriage may be a means of removing that
resentment and hatred, then he is enjoined to go ahead with arranging a
marriage for two reasons:
Because the woman has received
a proposal from a man who is compatible
In order to try to deal with
the hostility (between the families).
Al-Tirmidhi (1084) narrated that Abu Hurayrah (may Allah be
pleased with him) said: The Messenger of Allah (blessings and peace of Allah
be upon him) said: “If one of you receives a marriage proposal (for his
daughter or other female relative under his care) from one whose religious
commitment and good character are pleasing to you, then give (your daughter
or female relative) to him in marriage, for if you do not do that there will
be turmoil in the land and a great deal of mischief.”
Classed as hasan by al-Albaani in Saheeh al-Tirmidhi.
But if the guardian fears that there will be a renewal of the
problems and that his daughter may be wronged and ill-treated by this
family, and they will not treat her kindly, then in this case it is
permissible for him to refuse this marriage, because the guardian is acting
in the interests of the one who is under his guardianship, and her interests
in this case are served by not marrying this man.
And Allah knows best.