What is the ruling of Islamic law regarding a guardian's inability to financially continue sponsoring an orphan, and is he obligated to pay the sponsorship?

The Shari'ah encourages the sponsorship of orphans, and has assigned a great reward for it, as the Prophet, peace and blessings be upon him, said: "I and the guardian of the orphan will be in Paradise like this." If you are unable to spend on him, there is no blame upon you, because it is a voluntary act, not an obligation. The Prophet, peace and blessings be upon him, clarified the levels of spending, prioritizing oneself, then one's family, then one's relatives.