How sound is the circulating story about Nu'ayman when he lied and claimed that Suwaybit ibn Harmalah was a slave and that he sold him, and did the Prophet (peace be upon him) and the Companions laugh at Nu'ayman's action?

The story of Nu'ayman and Suwaybit—which occurred between Abu Bakr and some of his companions during a trade journey—can be summarized as Nu'ayman jokingly selling Suwaybit for ten camels. The Prophet (peace be upon him) and his companions laughed about it for a year.

Scholars have ruled that the chain of narration for this story is weak, and that it contradicts the prophetic prohibition against frightening a Muslim, based on his (peace be upon him) saying: "It is not permissible for a Muslim to frighten a Muslim."

Even if it were authentic, scholars have explained that it does not indicate the Prophet's (peace be upon him) approval of frightening Muslims through jokes. Rather, his (peace be upon him) and his companions' laughter at that story was similar to their laughter at matters of Jahiliyyah (pre-Islamic ignorance) that later became forbidden in Islam. Lawful joking is that which does not involve frightening others, and what people do by taking possessions as a joke is haram (forbidden), due to the fright it causes.