Salim Abu Al Nadr, client of ‘Umar bin ‘Ubaid Allaah that is Ibn Ma’mar who Salim was his (‘Umar’s) secretary reported “When ‘Abd Allah bin Abi Afwa went out to the Haruriyyah (Khawarij), he wrote to him (‘Umar bin ‘Ubaid Allaah), The Messenger of Allah(ﷺ) said on a ceratin day when he was fighting with the enemy. O people do not desire to meet the enemy, ask Allaah, Most High, for health and security. When you meet them (the enemy) have patience and endurance, you should know that paradise is under the shade of swords. He then said “O Allaah, Who sends down the Book, makes the cloud to travel and rotes the confederates, tout them and give us victory over them.”