Can the son of the paternal uncle inherit, and is it permissible to make a bequest to a righteous person who is not among the heirs?

The wife receives one-fourth as a prescribed share due to the absence of children. The remainder goes to the paternal uncle's son by way of ta'sib (residuary inheritance). A will (wasiyya) for one-third of the wealth is permissible for the righteous, the poor, and the needy. This is recommended, and it does not take effect for more than one-third unless the heirs agree. It is advisable to establish an endowment (waqf) as an ongoing charity (sadaqah (definition) jariyah) so that its reward continues after death, just as Umar ibn al-Khattab, may Allah be pleased with him, endowed his land.