Quran 2:179 — The Heifer (Al-Baqarah)

Equivalence is a life saving law for you, O you who possess intelligence, that you may be righteous.

[2:178] O you who believe, equivalence is the law decreed for you when dealing with murder—the free for the free, the slave for the slave, the female for the female. If one is pardoned by the victim's kin, an appreciative response is in order, and an equitable compensation shall be paid. This is an alleviation from your Lord and mercy. Anyone who transgresses beyond this incurs a painful retribution.

[2:180] It is decreed that when death approaches, you shall write a will for the benefit of the parents and relatives, equitably. This is a duty upon the righteous.