Is the wife's unforgiveness of her unjust co-wife—who did not apologize—considered a form of "musḥaḥanah" (rancor/dispute) that prevents forgiveness on the night of the 15th of Sha’ban, according to the Prophet's (PBUH) saying: "Indeed, Allah looks down on the night of the 15th of Sha’ban and forgives all of His creation except for a polytheist or a musḥaḥin (one who harbors rancor or dispute)"?

It is stated in the Hadith (definition) that the gates of Paradise are opened on Mondays and Thursdays, and every servant who does not associate anything with Allah is forgiven, except for a man between whom and his brother there is animosity (enmity and hatred). It is then said: "Delay these two until they reconcile." The blameworthy mushahin (one who harbors animosity) is he who antagonizes his brother without right, due to personal whims. It is permissible to abandon a Muslim if he is harmful and does not accept advice, in order to دفع ضرره (repel his harm), and this does not fall under the threat against the mushahin. For abandonment here is prescribed to repel harm and ceases when the harm ceases. It is not permissible to abandon a Muslim for more than three days except for a valid excuse. The best and most excellent course of action is to endure harm and repel it with kindness, for recompense is of the same nature as the deed, and whoever pardons his brethren will attain Allah's pardon and mercy.