Tafsir of Al-Baqarah 2:194

(The sacred month is for the sacred month): The polytheists fought them during the year of Hudaybiyyah in the month of Dhu al-Qi'dah with light combat, using arrows and stones. When it was time for them to go out for the Umrat al-Qada (the compensatory minor pilgrimage) during that same month, they were reluctant to fight them out of respect for its sanctity. Thus, it was said: This (sacred month) is for that [previous] sacred month, and the violation of it is matched by the violation of it; so do not be concerned by it.

(And sacred things are subject to legal retribution): Meaning, the matters that must be upheld—their very selves are [subject to] (retribution), or [the principle of] compensation. This contains the establishment of the argument for the previous ruling, as if it were said: Do not be concerned about entering it by force and violating the sanctity of this month initially by overcoming [them], for (sacred things) are subject to retribution; thus, the obstruction [of the pilgrimage] has as its retribution the entry by force.

(So if they fight you, kill them):

(Whoever has transgressed against you, then transgress against him in the same way he has transgressed against you): This is a summary of what preceded it, and it is more specific in meaning than the former. The first [verse] includes instances such as violating the sanctity of Ihram, hunting, or [uprooting] plants, unlike this one. It serves as an emphasis for His saying, "The sacred month is for the sacred month," and this is not contradicted by it being a summary linked with the fa (so), for the command here is for permissibility, as pardoning is [also] permissible.

(Man/Whoever) can be interpreted as conditional or as a relative pronoun; in the latter case, the fa is an explainer within the predicate, and the ba (in bimithli) allows for the possibility of being an augmentation or otherwise.

Al-Shafi'i used this verse as evidence that a killer should be killed in the same manner as he killed, whether by a sharp weapon, strangulation, burning, starvation, or drowning; to the extent that if he threw him into fresh water, he should not be thrown into salt water. It was also used as evidence that whoever usurps something and destroys it is obligated to return its equivalent (mithl). The equivalent may be based on form, as in things that have likes, or it may be based on meaning, as in value (qimah) for things that have no equivalent.

(And fear Allah regarding seeking victory for yourselves, and refraining from transgression in what you have not been permitted to do, and know that Allah is with the righteous) with support and aid.