يَا أَيُّهَا النَّاسُ لَا تَتَمَنَّوْا لِقَاءَ الْعَدُوِّ وَسَلُوْا اللَّهَ الْعَافِيَةَ، فَإِذَا لَقِيْتُمُوْهُمْ فَاصْبِرُوْا، وَاعْلَمُوْا أَنَّ الْجَنَّةَ تَحْتَ ظِلَالِ السُّيُوفِ.

Yaa ayyuhan naas, laa tatamannaw liqaa’al ‘aduyyi wa salullaahal ‘aafiyah, faa idhaa laqitumuhum faasbiru waa’lamu annal jannata tahta zilaalis suyyuf.

O people! Do not wish to face the enemy (in a battle) and ask Allah to save you (from calamities) but if you should face the enemy, then be patient and let it be known to you that Paradise is under the shades of swords.

Reference: Bukhari: 2966