ʿAbdullah bin Abi ʿAufa wrote and I read what he wrote that Messenger of Allah ﷺ said, "When you face them ( i.e. your enemy) then be patient."  

أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ إِذَا لَقِيتُمُوهُمْ فَاصْبِرُوا