Is stinginess a sin or a disease, and what is its punishment from Allah if it is a sin, and what is its proof?

Stinginess becomes a sin if it pertains to an obligation, such as withholding mandatory zakat (definition) or the maintenance of someone whose support is obligatory. It can even escalate to major sins, like withholding zakat and essential maintenance, due to Allah's saying: {And let not those who withhold what Allah has given them of His bounty think that it is good for them. Rather, it is bad for them. They will be encircled by what they withheld on the Day of Resurrection.} As for stinginess regarding what is not obligatory, it is a serious ailment, but it is not considered a sin. It has been narrated in a hadith (definition) that the Prophet, peace and blessings be upon him, said: "And what disease is more harmful than stinginess?"