Abstract
The research tackles the will linguistically and idiomatically beside its bases, conditions, and the fiqh of the legal rules detected from the detailed proofs in the glorious Koran and sunna. Many modes of wills that express the nature and understanding of the Mosuli society have appeared. It is owed to the importance of will; it is legal side that should be applied in a way that preserves the Mosuli family and society from decay.