Quran 2:181 — The Heifer (Al-Baqarah)

If anyone alters a will he had heard, the sin of altering befalls those responsible for such altering. GOD is Hearer, Knower.

[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.

[2:182] If one sees gross injustice or bias on the part of a testator, and takes corrective action to restore justice to the will, he commits no sin. GOD is Forgiver, Most Merciful.