When the Prophet (ﷺ) died and Abu Bakr became his successor and some of the Arabs reverted to disbelief, `Umar said, "O Abu Bakr! How can you fight these people although Allah's Messenger (ﷺ) said, 'I have been ordered to fight the people till they say: 'None has the right to be worshipped but Allah, 'and whoever said, 'None has the right to be worshipped but Allah', Allah will save his property and his life from me, unless (he does something for which he receives legal punishment) justly, and his account will be with Allah?' "Abu Bakr said, "By Allah! I will fight whoever differentiates between prayers and Zakat as Zakat is the right to be taken from property (according to Allah's Orders). By Allah! If they refused to pay me even a kid they used to pay to Allah's Messenger (ﷺ), I would fight with them for withholding it." `Umar said, "By Allah: It was nothing, but I noticed that Allah opened Abu Bakr's chest towards the decision to fight, therefore I realized that his decision was right."
Exposition of Hadith on Apostasy
This narration from Sahih al-Bukhari (6924, 6925) addresses the critical matter of apostasy and the obligation to combat those who abandon Islam after embracing it. The initial hesitation of Umar (RA) stemmed from his understanding of the Prophet's statement regarding the protection granted by the declaration of faith.
Abu Bakr's Legal Reasoning
The noble Caliph Abu Bakr (RA) demonstrated profound jurisprudential insight by recognizing that the rejection of zakat constitutes a rejection of Islam's fundamental pillars. His declaration "I will fight whoever differentiates between prayers and Zakat" establishes the principle that Islam's obligations are inseparable.
The refusal to pay zakat, which they had previously given to the Messenger (ﷺ), manifested their apostasy and rebellion against Islamic governance. This was not merely a financial matter but a rejection of divine commandments.
Consensus of the Companions
Umar's (RA) eventual agreement demonstrates the collective wisdom of the Sahaba. His statement "Allah opened Abu Bakr's chest towards the decision to fight" shows how divine guidance operates through the consensus of the righteous leadership.
This incident established the permanent ruling that those who apostatize from Islam and take up arms against the Muslim community must be combated until they return to the fold of Islam.