Sayyiduna Abu Hurairah (may Allah be pleased with him) narrates: When the Prophet Muhammad (peace and blessings be upon him) passed away and Sayyiduna Abu Bakr (may Allah be pleased with him) became the Caliph, and some people among the Arabs turned to disbelief, Sayyiduna Umar (may Allah be pleased with him) said to Sayyiduna Abu Bakr (may Allah be pleased with him): "How will you fight against these people when the Prophet Muhammad (peace and blessings be upon him) said: 'I have been commanded to fight the people until they say: There is no deity except Allah. Whoever says: There is no deity except Allah, he will protect his wealth and his life from me, except for its due right, and his reckoning is with Allah the Exalted.'"

Sayyiduna Abu Bakr (may Allah be pleased with him) replied: "By Allah! I will surely fight against the one who differentiates between prayer and zakat. Indeed, zakat is the due right of wealth. By Allah! If they refuse to give me even a rope which they used to give to the Prophet Muhammad (peace and blessings be upon him), I will fight them for their refusal."

Sayyiduna Umar (may Allah be pleased with him) says: "By Allah! I realized that Allah the Exalted had opened the chest of Sayyiduna Abu Bakr (may Allah be pleased with him) regarding fighting, and I came to know that this stance was correct."