Is it permissible for a son to perform Hajj on behalf of his sick and incapacitated father if the father was not aware of it beforehand?

If the father does not grant permission to his son to perform Hajj on his behalf, then the Hajj is counted for the son, not for the father. This is because a condition for performing Hajj on behalf of a living person is their permission. The Fiqh Encyclopedia states that it is not permissible to perform Hajj on behalf of another without their command, as representation is only established by command. Al-Mawardi mentioned that whoever performs Hajj on behalf of a living person without their command, the Hajj is counted for the one performing it, not for the one on whose behalf it was performed. A similar ruling is found in the books of the Hanbalis.