What is the ruling on an illiterate woman's vow to read a complete recitation of the Quran for the reformation of her husband, while delegating someone else to read it?

If someone vowed to read a complete recitation of the Quran but is illiterate and cannot read, then he must offer expiation for a broken oath (kaffarat yamin (definition)) due to his inability to fulfill the vow, as stated in the hadith (definition): "Whoever makes a vow he cannot fulfill, its expiation is the expiation for an oath." It is not permissible for him to appoint someone else to read on his behalf, because reading the Quran is a physical act of worship (ibadah badaniyyah) that does not permit deputization, unlike financial acts of worship such as giving charity, or cases where there is a specific legal text (nass shar'i) allowing for deputization, such as fasting on behalf of the deceased or performing Hajj for someone who is incapacitated.