Battle of Siffin
These injunctions were honored by the second caliph, Umar, during whose reign (634–644) important Muslim conquests took place. In addition, during the Battle of Siffin, the caliph Ali stated that Islam does not permit Muslims to stop the supply of water to their enemy. In addition to the Rashidun Caliphs, hadiths attributed to Muhammad himself suggest that he stated the following regarding the Muslim conquest of Egypt: