Why did the Sahaabah use burning with fire as a punishment for some crimes?
To sum up: what may be stated definitively is that the Sahaabah (may Allah be pleased with them) did not deliberately go against the prohibition on punishment by burning. What has been narrated from some of them (concerning that) is either not saheeh (sound), or it is saheeh but they are excused for what they did on the basis of ijtihaad, because they were qualified to engage therein. If the mujtahid strives his utmost to issue a correct verdict and fatwa but makes a mistake, he is rewarded and is not regarded as having sinned. It was narrated from ‘Amr ibn al-‘Aas, that he heard the Messenger of Allah (blessings and peace of Allah be upon him) say: “If a judge passes a judgement having striven to reach a decision, and he gets it right, he will have two rewards. If he passes a judgement having striven to reach a decision and he gets it wrong, he will have one reward.” Narrated by al-Bukhaari (7352) and Muslim (1716). For more information, please see Sharh al-Kawkab al-Muneer (4/491-492) And Allah knows best.
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