When Imam Ali (AS) arrived at the Safin area, Muawiya blocked the way of water from every side so that the army of Imam stuck in a predicament and cannot fight well. Imam Ali (AS) ordered a group to open the way of water and this group was led by Hazrat Hussein. With that small groupو Hazrat Hussein attacked them in order to provide water. The soldiers who were protecting the way of water escaped. Then the army of Imam Hussein was provided by water. Some people asked Imam Ali (AS) to block the way of water for Muawiya, but Imam Ali (AS) said: I swear to Allah, I will not do this, then he sent a representative to Muawiya to inform him that the way of water is not blocked and they can take as much water as they want.
source : erfan.ir
