Did the Prophet, peace and blessings be upon him, not say: "None punishes with fire except Allah," and is burning forbidden in Islamic law, and if so, is he who commits it not sinful?

The Prophet, peace and blessings be upon him, forbade punishment by fire. Therefore, the punishment of burning by fire is prohibited by Islamic law. However, the majority of scholars have made an exception to this general prohibition: burning as a retribution (qisas) or as a reciprocal punishment for someone who burned another, based on the noble verses that call for retaliation in kind. As for what has been attributed to the Companions, such as Ali, Abu Bakr, and Khalid ibn al-Walid, regarding their burning of certain offenders, either these narrations are not authentic, or they are authentic, but the Companions were excused in their actions. Perhaps the hadith of prohibition did not reach them, or they forgot it, or they interpreted the prohibition as being disliked rather than strictly forbidden. And a mujtahid (one who strives to deduce Islamic law) who errs is still rewarded for their effort.