The Banu Sa'd (Arabic: بنو سعد‎ / ALA-LC: Banū Saʿd) was one of the leading royal tribes of Arabia during the Islamic prophet Muhammad's era. The Banu Sa'd also known as Sood and Saud, were a subgroup of the larger Hawazin tribal confederation. They had close family relations with Muhammad.They were great warriors and fought many battles with Muhammad against enemies of Islam. Halima Sadia, Muhammad's wet nurse, belonged to this tribe. They migrated on the order of Muhammad to Subcontinent, Africa and Europe to fight against Polytheism.