Sayyiduna Ali (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) said: "The protection (dhimmah) of the Muslims is one; even the lowest of them is equal in it. Whoever violates the protection given by a Muslim, upon him is the curse of Allah, the angels and all the people, and none of his worship, neither voluntary nor obligatory, will be accepted."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قتال أهل البغي / 16812