How is the inheritance divided among the wife, seven full sisters, and six sons of a full brother, if the deceased bequeathed his entire estate to his wife to disinherit his sisters and his nephew, and does the situation differ if he wrote down everything he owns to her?

If a man dies and leaves behind a wife, seven full sisters, and six full nephews, and no other heirs, then his wife receives one-fourth as a fard (fixed share), and his seven sisters receive two-thirds as a fard, and the remainder goes to the full nephews by ta’sib (residuary heirship).

As for his will bequeathing his entire estate to his wife, this is a bequest to an heir, which is forbidden by Sharia and is not enforceable unless approved by the adult heirs. If he transferred the ownership of the estate to her name outside of his death-illness, and delivered it to her, and she disposed of it as an owner, then it is a valid gift, unless his intention was to harm the heirs.

It is obligatory to refer inheritance matters to the Sharia courts for investigation, as there may be wills, debts, or rights that take precedence over the rights of the heirs.