This also proves that the vow (such as Hajj, etc.) should be fulfilled from the entire wealth of the deceased, because the Prophet (peace be upon him) likened the vow of Hajj to a debt (and a debt is paid from the whole wealth, not just one third of it).

Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates that a woman made a vow to perform Hajj, then she passed away. Her brother came to the Messenger of Allah (peace be upon him) and asked about this issue. The Prophet (peace be upon him) said: "What do you think, if your sister had a debt, would you pay off her debt?" He replied, "Yes." The Prophet (peace be upon him) said: "Then fulfill Allah's debt (the vow of Hajj), for Allah's debt is more deserving of being paid."