Why did the righteous fear miraculous occurrences and strive to conceal them?

The righteous fear miraculous occurrences (karamat) because they might be a trial (fitnah) and a gradual enticement (istidraj), leading the servant to become deluded, arrogant, and cut off from Allah. They conceal these occurrences—unless there is a need or benefit—to avoid fame and seeking people's praise, and because concealment is closer to sincerity (ikhlas (definition)).

Those who know Allah (Ulama billah) consider karamat to be a type of trial and tribulation, and a worldly indulgence for the servant. Thus, they fear becoming preoccupied with them and consequently cut off from Allah.

Abu Hafs al-Naysaburi wept when a miracle appeared to him, fearing that Allah was giving him his share in this world and would leave him poor in the Hereafter. The gnostics (arifun) did not pay attention to extraordinary phenomena; rather, their concern was with knowing Allah, fearing Him, loving Him, and finding solace in Him.

A servant strengthens his sincerity and truthfulness to Allah such that he dislikes anyone among creation becoming aware of his state and station with Him. He conceals his spiritual states out of jealousy for them, lest they be tainted by the impurities of others.

The truthful conceal karamat out of jealousy for them, and they do not reveal them except for an overriding benefit, such as an argument against a denier of truth, or a necessity that requires their manifestation.