Is it permissible to join together in marriage a woman and her paternal aunt or maternal aunt, and what is the evidence on this?
Answer:
All perfect praise be to Allah the Lord of the Worlds. May His peace and blessings be upon our Prophet Mohammad and upon all his family and companions.
It is prohibited for a Muslim to join together (in marriage to him) a woman and her paternal aunt or a woman and her maternal aunt because: Allah's Messenger (Peace and blessings be upon him) said: "A man must not join together (in marriage to him) a woman and her paternal aunt or a woman and her maternal aunt." [Agreed upon].
There is scholarly consensus on this and it was reported by Ibn Al-Monther, Ibn Qhoddamah and others. And Allah the Almighty knows best.