Carrying out a death sentence for a severe crime is not left to an anonymous executioner. Instead, it demands the direct, physical involvement of the very people who testified against the accused, followed by the participation of the entire community. This process carries deep legal, psychological, and spiritual weight. The requirement for the witnesses to act first applies to each witness individually [אבן עזרא, ביאור יש״ר]. They are commanded to initiate the execution, and the rest of the community is forbidden from stepping in before them [הכתב והקבלה, אדרת אליהו].
In practice, the procedure unfolds in stages. One witness pushes the condemned person. If this does not result in death, the second witness throws a stone at him. Only if the person still survives do the rest of the people join in to complete the execution [תורה תמימה, רלב״ג, מלבי״ם]. This requirement is an absolute legal condition. If a witness's hand is cut off after giving testimony, the condemned person is spared from death. Since the execution cannot be carried out literally by the hand of the witness, the sentence cannot be fulfilled [הכתב והקבלה, תורה תמימה, מלבי״ם].
The primary approach among commentators is that placing the burden of execution on the witnesses serves to prevent false testimony. It forces the witnesses to confront the heavy responsibility of their words. While a person might easily tell a lie in court, being forced to personally kill the victim of their false accusation is likely to make them recoil and retract their testimony at the last moment [רלב״ג, ביאור שטיינזלץ]. Another perspective notes that the witnesses are the only ones who experienced the event firsthand, while the rest of the community relies on secondhand information [תורה תמימה]. Those who did not see the crime might hesitate or feel guilty, worrying that the condemned might be innocent. When the community sees the witnesses stepping forward to strike without hesitation, it reassures them and proves that the witnesses are entirely certain of the person's guilt [בכור שור].
The final demand is to completely remove the evil from the community, which means no pity can be shown to the guilty party [אם למקרא]. If the court is unable to carry out the execution through the specific method prescribed, they are obligated to end the person's life in any other possible way to ensure the danger is removed from society [תורה תמימה, מלבי״ם]. Conceptually, one might wonder why the sinner is not kept alive to allow for repentance. The explanation is that executing the guilty person is ultimately an act of mercy for the entire community. Leaving the sinner alive is compared to leaving an infected limb attached to a body; removing the limb may seem cruel to the limb itself, but it saves the entire body from a deadly spreading infection. Beyond the physical removal of the person, this act uproots the spiritual power of impurity and corruption generated by the sin, a destructive force that could otherwise lead others in the community to fail [אלשיך].