Could you please elaborate on verse 33 of Surat Al-Isra?

Allah Almighty's saying: "And do not kill the soul which Allah has forbidden, except by right" is a prohibition against killing an inviolable soul except by right, such as apostasy, adultery for the married person, and retribution (qisas). And His saying: "And whoever is killed unjustly, We have certainly given his heir authority" means that the heirs of the deceased have the right to retribution, or pardon, or to take the blood money (diyah). And His saying: "So let him not exceed in killing" is a prohibition for the heir against exceeding the limit in retribution, such such as killing more than one person or mutilating the deceased. "Indeed, he has been aided" means that the heir is supported and assisted by Allah.