A man said to him: "Why don't you go out and fight?" He said: "I heard the Messenger of Allah [SAW] say: 'Islam is built on five (pillars): Testimony that there is none worthy of worship except Allah, establishing Salah, giving Zakah, Hajj, and fasting Ramadan.'"  

سَمِعْتُ رَسُولَ اللَّهِ ﷺ يَقُولُ بُنِيَ الإِسْلاَمُ عَلَى خَمْسٍ شَهَادَةِ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ وَإِقَامِ الصَّلاَةِ وَإِيتَاءِ الزَّكَاةِ وَالْحَجِّ وَصِيَامِ رَمَضَانَ