It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "I have been commanded to fight people until they affirm the kalimah, begin performing the prayer and start paying zakah. When they do this, they will have protected their wealth and their blood from me, except by its right, and their reckoning rests with Allah."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13120