Narrated 'Abdullah bin 'Amr: 'A man asked the Prophet , "What sort of deeds of Islam are good?" The Prophet replied, "To feed the poor and greet those whom you know and those whom you do not Know" '
- (Sahih Bukhari, Vol-1 : hadith-11)
Narrated Ibn 'Umar: 'Allah's Apostle said: "I have been ordered to fight against the people until they testify that none has the right to be worshipped but Allah and that Muhammad is Allah's Apostle, and offer the prayers perfectly and give the obligatory charity, so if they perform that, then they save their lives and property from me except for Islamic laws and then their reckoning will be done by Allah." '
- (Sahih Bukhari, Vol-1 : hadith-24)