It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that a woman made a vow to perform Hajj, but she passed away before fulfilling it. Her brother came to the Prophet (peace and blessings be upon him) and asked him about this issue. The Prophet (peace and blessings be upon him) said: "Tell me! If your sister had a debt, would you pay it off or not?" He replied in the affirmative. The Prophet (peace and blessings be upon him) said: "Then pay Allah's debt as well, for it is more deserving to be fulfilled."