The World Federation One Stop Fiqh

Ruling 2718

If a person who notices the signs of his approaching death owes the one-fifth tax (khums), alms tax (zakat), or maẓālim3 but is unable to pay it at present, in the event that he has sufficient wealth to pay it, or he deems it probable that someone else will pay it, he must make arrangements such that he is confident that his debt will be paid after his death. For example, he must make a will for a trusted individual [to pay it]. The same applies if hajj is obligatory for him and he is unable to get a representative (nāʾib) [to perform hajj on his behalf] at present. However, if he is able to pay the debt of his religious dues at present, he must pay it without delay even if he does not notice the signs of his approaching death.

3 Maẓālim refers to property which has been unrightfully or unknowingly taken.