The first is that this is the ruling of the Messenger of Allah ﷺ, and we are therefore obliged to submit to it; for the reality of Islam is not complete except through submitting to what the Messenger ﷺ has ruled. Allah, may He be exalted, says:
“By your Lord, they will not truly believe until they make you judge in all disputes between them, then find no discomfort within themselves regarding what you have decided, and submit wholeheartedly.” [al-Nisa’ 4:65]
If someone says: We submit to the command of the Messenger ﷺ, but how do we answer the saying of Allah, may He be glorified and exalted:
“No soul burdened with sin will bear the burden of another. Even if a heavily burdened soul calls for help with its burden, none of it will be carried for it—even by a close relative.” [Fatir 35:18]
The answer is that this concerns sins and misdeeds. As for support, assistance, and mutual aid, that is another matter. Thus, making the liable agnatic relatives responsible for the blood-money falls under support and mutual aid, just as we require a wealthy person to provide maintenance for his poor relative.
Allah the Exalted also says:
“And that a person will have nothing except what he has striven for.” [al-Najm 53:39]
The scholars are unanimously agreed that if a man gives someone a gift from his wealth, which he acquired through his own earnings and hard work, that is permissible, even though it is not from the recipient’s own striving. This shows that what is meant by the verse is that a person has no reward except the reward for what he himself has striven and done.
The second is that a person often makes mistakes; and if we were to hold him liable for every mistake he makes, his wealth would be exhausted. It is therefore wise that he should be supported and assisted.
If you say: This wisdom existed in the time of the Companions and in earlier times, but it has a negative consequence in our present age: when a person knows that his liable agnatic relatives will bear the blood-money on his behalf, he becomes reckless and does not