Is it permissible for a Muslim to sell urns used to hold the ashes of the deceased after cremation, which have a commemorative meaning for their families?

It is not permissible to cremate a deceased person, whether Muslim or non-Muslim, due to the disrespect and indignity it entails, which is contrary to the concept of honoring the dead. It is not permissible for a Muslim to assist anyone in committing a sin, based on the Almighty's saying: (And cooperate in righteousness and piety, but do not cooperate in sin and aggression) Al-Ma'idah/2. So, whoever assists in a sin will incur a portion of its guilt commensurate with their participation. This includes selling or renting anything when it is known that the buyer or renter will use it for a prohibited purpose.