Who is responsible for the financial support of the children, the wife, and the husband's mother after the husband's death, and are they the 'Asabat (agnatic heirs) in order of precedence, and what is the evidence for that?

The maintenance of a minor whose father died poor falls upon his heirs from the 'Asabah (agnates) and the Ashab al-Furood (sharers), each according to their inheritance, based on the Almighty's saying: "And upon the heir is the like of that." As for the maintenance of the deceased's poor wife and mother, it falls upon their own heirs.