Surah Al Baqarah Tafseer

فَمَن بَدَّلَهُ بَعْدَمَا سَمِعَهُ فَإِنَّمَا إِثْمُهُ عَلَى الَّذِينَ يُبَدِّلُونَهُ

Then whoever changes it after hearing it, the sin shall be on those who make the change.

means, whoever changed the will and testament or altered it by addition or deletion, including hiding the will as is obvious, then

فَإِنَّمَا إِثْمُهُ عَلَى الَّذِينَ يُبَدِّلُونَهُ

(the sin shall be on those who make the change).

Ibn Abbas and others said,

"The dead person's reward will be preserved for him by Allah, while the sin is acquired by those who change the will."

إِنَّ اللّهَ سَمِيعٌ عَلِيمٌ

Truly, Allah is All-Hearer, All-Knower.

means, Allah knows what the dead person has bequeathed and what the beneficiaries (or others) have changed in the will.

Allah's statement:

فَمَنْ خَافَ مِن مُّوصٍ جَنَفًا أَوْ إِثْمًا فَأَصْلَحَ بَيْنَهُمْ فَلَ إِثْمَ عَلَيْهِ إِنَّ اللّهَ غَفُورٌ رَّحِيمٌ