How did Abu Bakr fight those who withheld zakat, given that the Prophet, peace be upon him, said: "I have been forbidden from killing those who pray," and his saying about the leader of the Khawarij: "Perhaps he prays"?

Abu Bakr, may Allah be pleased with him, fought those who withheld zakat with the consensus of the Companions, and this consensus is a proof that must be followed. This does not mean that consensus takes precedence over the texts of revelation; rather, it is derived from them. The hadith prohibiting the killing of those who pray is not absolute, as evidenced by the killing of an apostate, or a praying person as a retribution (qisas), or as a punishment (had) (such as the married fornicator, the rebel, and the highway robber). Abu Bakr and Umar understood this qualification, as Abu Bakr said: "By Allah, I will fight whoever differentiates between prayer and zakat, for zakat is the right of wealth," and Umar agreed with him on this.