Purity: Limits on Funding the Kafan Without a Specific Will

Practical Laws of Islam as per the teachings of Ayatullah Sistani

Ruling 562:

If a deceased person has not made a will stipulating that the cost of his kafan must be taken from the one-third of his estate, and if one wants to take it out from his estate, he must not take more than what was mentioned in Ruling 560. For example, the recommended quantity of the kafan must not be taken from the deceased’s estate in an amount that is uncommon and more than what is appropriate to the deceased’s status. Similarly, if one pays more than the usual price for the kafan, he must not pay the extra amount from the deceased’s estate. However, he can pay for it from the share of the heirs who are bāligh with their consent.

-Ayatullah Sistani, Practical Laws of Islam, Purification (Taharah)