But if anyone fears partiality or wrongdoing(187) on the part of the testator, and makes peace between (The parties concerned), there is no wrong in him: For Allah is Oft-forgiving, Most Merciful.
187 A verbal will is allowed but it is expected that the testator will be just to his heirs and not depart from what is considered equitable. For this reason definite shares were laid down for heirs later (see 4:11 , etc.). These define or limit the testamentary power, but do not abrogate it. For example, amongst kin there are persons (e.g., an orphan grandson in the presence of surviving sons) who would not inherit under the intestate scheme, and the testator might like to provide for them. Again, there may be outsiders for whom he may wish to provide, and jurists have held that he has powers of disposition up to one-third of his property. But he must not be partial to one heir at the expense of another, or attempt to defeat lawful creditors. If he tries to do this, those who are witnesses to his oral disposition may interfere in two ways. One way would be to persuade testator to change his bequest before he dies. The other way would be, after death, to get the interested parties together and ask them to agree to a more equitable arrangement. In such a case they are acting in good faith, and there is no fraud. They are doing nothing wrong. Islam approves of every lawful device for keeping brethren at peace, without litigation and quarrels. Except for this, the changing of the provisions of a Will is a crime, as it is under all Law.