Concept:
Muslim law classifies marriages into three categories based on their legality: Sahih (Valid), Batil (Void), and Fasid (Irregular).
• Sahih: A marriage that fulfills all legal requirements.
• Batil: A marriage that is unlawful from the beginning (e.g., marrying a close blood relative).
• Fasid: A marriage that has a temporary impediment which can be removed.
Step 1: Analyzing the restriction on polygamy.
A Muslim male is permitted to have a maximum of four wives at any given time.
Marrying a fifth wife creates a
"temporary impediment."
The impediment is temporary because if the husband divorces one of the first four wives, the fifth marriage can become valid.
Step 2: Determining the legal consequence.
Under Sunni Law, a fifth marriage is considered
Irregular (Fasid).
It is not void (Batil) because the flaw in the marriage is curable.
Children born out of an irregular marriage are considered legitimate, although the wife does not have a right to inherit from the husband if he dies before the marriage is regularized.