What is the ruling on one who usurps the rights of his siblings, claiming inability to make a living?

It is forbidden to consume a Muslim's property except in two cases:

The first is when one's sustenance is obligatory upon another, in which case one may take a reasonable amount for one's sustenance, even without the other's knowledge if they withhold it.

The second is when one is in a state of dire necessity, fearing for one's life, in which case one may consume from it what suffices to avert the necessity.

Other than these two cases, it is impermissible to consume a Muslim's property except with their permission, for the Prophet, peace be upon him, said: "Every Muslim's blood, property, and honor are sacred to another Muslim."