This hadith shows that he prohibited fighting in times of strife. Indeed, he commanded measures that make fighting impossible: withdrawing or rendering one’s weapons unusable. This applies both to those compelled to fight and to others.
He then explained that if someone compelled to fight is wrongfully killed, the killer will bear his own sin and that of the person killed. Likewise, in the account of Adam’s two sons, Allah Most High relates the words of the wronged brother:
“I want you to bear my sin and yours, and so become one of the people of the Fire. Such is the recompense of the wrongdoers.”
It is well established by the Sunnah and scholarly consensus that a person whose life is threatened by an assailant may defend himself. The scholars differed only over whether he is obliged to defend himself by fighting. There are two views, both reported from Ahmad. According to the first, he must defend himself, even if he has not joined the battle line. According to the second, he may refrain from defending himself. As for initiating combat in times of strife, this is undoubtedly impermissible.
The point is that someone compelled to fight in times of strife is not permitted to fight. Rather, he must render his weapons unusable and patiently endure, even until he is wrongfully killed. How much more, then, does this apply to someone compelled to fight against the Muslims alongside a faction that has departed from the laws of Islam, such as those who withhold zakah, apostates, and others like them? There is no doubt that if he is compelled to join their ranks, he must refrain from fighting, even if the Muslims kill him. This is just as if the disbelievers compelled him to join their battle line to fight against the Muslims, or as if one man compelled another to kill a Muslim whose life is inviolable. By the consensus of the Muslims, he is not permitted to kill that person, even if compelled under threat of death. For saving his own life by killing that person whose life is inviolable has no greater claim than the reverse.