When the Messenger of Allah ﷺ passed away and Abu Bakr was appointed as his successor, some of the Arabs apostatized. Umar said to Abu Bakr, "How can you fight these people when the Messenger of Allah ﷺ said, 'I have been commanded to fight people until they say, There is no god but Allah. Whoever says, There is no god but Allah, has secured from me his wealth and his life, except for what is due upon them, and his reckoning is with Allah'?"Abu Bakr replied, "By Allah, I will fight anyone who differentiates between prayer and zakat, for zakat is the due of wealth. By Allah, if they withhold from me even a young goat that they used to give to the Messenger of Allah ﷺ, I will fight them for withholding it."Umar said, "By Allah, when I saw that Allah had opened Abu Bakr's heart to fighting them, I knew that he was in the right."
لما توفى رسول الله ﷺ واستخلف أبو بكر بعده وكفر من كفر من العرب، قال عمر لأبي بكر: كيف تقاتل الناس وقد قال رسول الله ﷺ: أمرت أن أقاتل الناس حتى يقولوا: لا إله إلا الله. فمن قال لا إله إلا الله عصم مني ماله ونفسه إلا بحقه وحسابه على الله. فقال: والله لأقاتلن من فرق بين الصلاة والزكاة، فإن الزكاة حق المال، والله لو منعوني عقالا كانوا يؤدونه إلى رسول الله ﷺ لقاتلتهم على منعه. فقال عمر: فوالله ما هو إلا أن رأيت الله قد شرح صدر أبي بكر للقتال فعرفت أنه الحق.
Bukhari narrated it in the chapter on holding fast to the Book and the Sunnah (7284), and Muslim in the Book of Faith (32:20), both from Qutayba bin Saeed, who said, Layth narrated to us, from Aqeel, from Zuhri, Ubaydullah bin Abdullah bin Utba bin Masud informed me, from Abu Hurairah, and he related it.Bukhari said afterward, Ibn Bukayr and Abdullah said, on the authority of Layth, "a female kid goat" (anaqan), and this is more sahih.I say, Ibn Bukayr is Yahya bin Abdullah bin Bukayr, and his narration from Layth appears in the chapter on calling back apostates to repentance (6924). And Abdullah is Abu Salih the Egyptian, the scribe of Layth. Bukhari's statement, "this is more sahih," means more sahih than the narration with "a rope" (iqalan).The word anaq, with the ain and the nun both vowelled with a fatha, refers to a female offspring of goats that has not yet reached one year of age.