Author: Dr. Muhammad Zia-ur-Rahman Azmi (رحمه الله)
But is it permissible for the heirs to deny the will? If they are certain that the person conveying the information is trustworthy, then they should not deny it. However, they are not obligated to confirm it either.
It can be said that if they are convinced of the trustworthiness of the informant, they should implement the will. However, if they have doubts—for instance, if the informant is a friend of the deceased and they suspect that he may have fabricated the information out of affection for the deceased—they are not required to confirm it.
(Source: Ibn Uthaymeen, "Liqaa al-Baab al-Maftooh," Vol. 21, Pg. 191)
Ruling on Executing a Will That Is Neither Written Nor Witnessed
If the heirs confirm the will, there is no harm in implementing it. However, if they deny its validity, it cannot be established.But is it permissible for the heirs to deny the will? If they are certain that the person conveying the information is trustworthy, then they should not deny it. However, they are not obligated to confirm it either.
It can be said that if they are convinced of the trustworthiness of the informant, they should implement the will. However, if they have doubts—for instance, if the informant is a friend of the deceased and they suspect that he may have fabricated the information out of affection for the deceased—they are not required to confirm it.
(Source: Ibn Uthaymeen, "Liqaa al-Baab al-Maftooh," Vol. 21, Pg. 191)