Among those whom the Companions fought—despite their acknowledgment of the two testimonies of faith, prayer, and other matters—were those who withheld zakat. As reported in the two Sahīh collections:

“Abu Hurayrah reported that ‘Umar ibn al-Khattāb said to Abū Bakr: ‘O successor to the Messenger of Allah, how can you fight the people when the Messenger of Allah, may Allah bless him and grant him peace, said: “I have been commanded to fight the people until they testify that there is no deity worthy of worship except Allah and that I am the Messenger of Allah. Once they say this, their lives and property are protected from me, except as its rightful requirements demand”?’

“Abū Bakr replied: ‘Did he not tell you, “except as its rightful requirements demand”? Zakat is one of its rightful requirements. By Allah, if they withheld from me even a young female goat that they used to give to the Messenger of Allah, may Allah bless him and grant him peace, I would fight them for withholding it.’

“‘Umar said: ‘As soon as I saw that Allah had opened Abū Bakr’s heart to fighting, I knew that this was right.’”

The Companions and the imams after them agreed that those who withhold zakat are to be fought, even if they perform the five daily prayers and fast the month of Ramadan. These people had no plausible grounds for doubt, and were therefore apostates. They are to be fought for withholding it, even if they acknowledge its obligation, as Allah has commanded.

It is reported that they said: ‘Allah commanded His Prophet to collect zakat in His words, “Take charity from their wealth,” but this obligation lapsed with his death.’ Likewise, the Prophet, may Allah bless him and grant him peace, commanded that those who would not desist from drinking wine be fought.

As for the other principle—ascertaining their circumstances—it is known that these