What is the ruling on joking about someone being extremely careful and meticulous in buying and scrutinizing goods, while recalling the verse: "then let him see which of them has the purest food [and] bring you a provision from it"?

The cure for obsessive whispers (waswas) is complete avoidance, as it is a disease that leads to great evil and can cause a person to lose their natural state. Ibn Hajar al-Haytami explained that the effective remedy for waswas is complete disregard for it, and that it will disappear after a short period. As for those who listen to it, it will increase until it drives them to the realm of the insane. The devil's whispers aim to lead the believer astray and into confusion. Al-Izz ibn Abd al-Salam and others said that the cure for waswas is to believe that it is a satanic thought and to fight that devil, thereby earning the reward of a mujahid (one who strives in the path of Allah).

Regarding the ruling on mocking people: If the intention is to belittle and mock someone, then that is forbidden by Islamic law. Allah Almighty has prohibited mockery, backbiting, calling by offensive nicknames, and gossip. It is stated in the noble Hadith (definition) that "A Muslim is the brother of a Muslim; he does not betray him, lie to him, or let him down." And "A Muslim's honor, wealth, and blood are sacred to another Muslim."