[Fighting Those Who Withheld Zakat]

Likewise, when it came to fighting the people who refused to pay zakat, ʿUmar said to Abū Bakr:
“How can we fight the people when the Messenger of Allah (Allah bless him and grant him peace) said, ‘I have been commanded to fight the people until they bear witness that there is no deity but Allah and that I am the Messenger of Allah; once they do so, their lives and property are inviolable to me—except for a right that is due’?”

Abū Bakr, may Allah be pleased with him, answered, “Did he not also say, ‘except for a right that is due’? Zakat is part of that due right. By Allah, if they were to withhold from me even a single young goat that they used to give to the Messenger of Allah (Allah bless him and grant him peace), I would fight them for withholding it.”

ʿUmar then said, “By Allah, as soon as I saw that Abū Bakr’s chest had opened to fighting, I knew it was the truth.”

[The Rank of the Ṣiddīq and the Rank of the Muḥaddath]

There are similar cases that show Abū Bakr’s precedence over ʿUmar, even though ʿUmar, may Allah be pleased with him, was a muḥaddath (one who receives inspired notions). The rank of the ṣiddīq (the utterly truthful confirmer) is above that of the muḥaddath, because the ṣiddīq takes everything the infallible Messenger says and does directly from him, whereas the muḥaddath receives certain matters in his heart—and his heart is not infallible—so he must measure what it contains against what the infallible Prophet brought.